Showing posts with label Interview Questions and Answers. Show all posts
Showing posts with label Interview Questions and Answers. Show all posts

Monday 29 December 2014

HTML interview questions and Answers

HTML interview questions and Answers

Question: What is full form of HTML?
Hyper Text Markup Language


Question: What is a html tag?
A tag tells the browser what to do with the data. html, body, title, a, ol and b are the most commons tags used in HTML.


Question: How can I include comments in HTML for 1 line and multiple line?
One line comment
<!-- This is a comment. -->
Multiple line comment
<!-- 
This is a comment
This is a comment
This is a comment
. -->



Question: Who is making the Web standards?
The World Wide Web Consortium



Question: What is the difference between XML and HTML?
XML is used for exchanging data, HTML is used to displaying the data in browser.


Question: How can you create an e-mail link?
<a href="mailto:email@domain.com">Email Me </a>



Question: Which html tags make a list that lists the items with numbers?

Example
<ol>
<li>hello</li>
<li>hello</li>
<li>hello</li>
</ol>



Question: What is a Hypertext link?
Hypertext link is used to navigate between one page to another page. Navigation can be same OR different website's pages.



Question: How do I center a table in html?
<div class="center">
...<br />
<table></table>
</div>
div.center {
text-align: center;
}


Question: How can I check for errors?
http://validator.w3.org/



Question: Can I have two or more actions in the same form?
No. you can't



Question: Can I have two or more form in the same page?
Yes, you can add multiple forms in a page.


Question: Is it possible to make the HTML source not viewable?
No


Question: How can I allow file uploads to my web site?
Use following to html code to display file upload button
<form action="upload.php" enctype="multipart/form-data" method="post">
File to upload: <input name="upload" type="file" /><br />
<input type="submit" value="Press" /> to upload the file!
</form>
Then use server side language to upload file to server.


Question: How do I create a link?
<a href="http://web-technology-experts-notes.in/">Web Technology Experts Notes</a>


Question: Is it possible to make the html source not viewable?
No, you can't.


Friday 26 December 2014

SEO Interview Questions and Answers

SEO Interview Questions and Answers




Question: What is full form of SEO?
Search Engine Optimization.


Question: What are two types of SEO?
On Page Optimization
Off Page Optimization


Question: What On-page optimization?
On-Page Optimization is way to "SEO optimize" of website by page coding. For Example add Meta Title, Meta Description, Meta Keywords, Content Quality, Meta Keyword Density, Outbound Links, Image Alt tag in website.


Question: What is off page Optimization?
On-Page Optimization is way to "SEO optimize" of website by adding your website links in other popular website. For Example Link building , Blog posting, Image Sharing, Video Sharing and Article submission etc of your website.


Question: What is meta tags?
Meta tag is combination of several meta tags but it included 4 major meta tags which are meta title, meta description, meta keywords and robots tags. These play vital role in SEO of website.


Question: What is Meta Title?
It display in the title of website in browser. It also show in search engine. This tag is important because it appear in search results.


Question: What is Meta Description?
We can describe about our page with use of Meta description. It is also used by Search engines for showing results in search engine.


Question: What is Meta Keywords?
Keyword is a "list of words" that is used for searching through Search Engines (Google, Bings etc). In each page of website, we add meta keywords that display in page source of website. Search engine crawl the website and meta keywords and when someone search that keywords, Search gives website links.


Question: What is Page Rank or PR?
Page Rank is a rank that has been provided by Google for each page of your website. This Rank ranges from 0 to 10, calculated by algorithm used by Google Web Search Engine.


Question: What is a Backlink?
Backlink means incoming links to our website from other sources like facebook, twitter, linkdin, google plus and ping etc.


Question: What are out bound Links(OBL)?
An outbound-link is a link from your website to another website. For example you have given link of another's website on your website & when any user click on same link Known as out bound links.



Question: What is Anchor Text?
It is a clickable hyperlink also known as link text. For Example
<a href="http://www.web-technology-experts-notes.in/2015/07/android-push-notification-api-in-php-send-notification-to-google-when-message-received.html">This is Anchor Text</a>


Question: What are the different method to control the robot?
  • Robots.txt
  • Robots Meta Tag
  • Rel= nofollow



Question: Where do you put your robots.txt?
you should put this in same folder where first file is call when website load.


Question: What is Googlebot?
Googlebot is the search bot (software) used by Google to Crawling, Caching and indexing of a webpage.


Question: What is the difference between SEO and SEM?
SEO stands for Search Engine Optimization whereas SEM stands for Search Engine Marketing.
SEO provides organic traffic to a website with the help of search engines while SEM involves the use of Google adwords like paid services.


Question: What are the method to content optimization?
  • Keyword density in content
  • Keyword Proximity
  • Keyword Prominence
  • Keyword Proximity



Question: Can you please tell the 5 most important on page factors?
  • Meta Title
  • Meta Description
  • Meta Keywords
  • Heading Tag
  • Image Optimization
  • Content Optimization



Question: What is Indexing?
Indexing is the process by which Google or other search engine store our website info in their database.


Question: What are the SEO tools do you use?
Google analytics, keyword search, Alexa, open site explorer, Google Webmaster.


Question: What is keyword stemming?
The process of finding out the root word from the search query is referred as keywords stemming.


Question: What do you mean by Cloaking?
Cloaking is a deceptive way of optimizing search.
In this technique a different content will be searched by the search engine than currently searched by the users.


Question: How many characters limits in Title tag?
70 characters in title tag.


Question: What is Google Sandbox?
Google sandbox is an imaginary area where new websites and their search rating are put on hold until they prove worthy for ranking. means it is used to checks the standard of the website.


Question: Name few Black Hat SEO techniques?
  • Link Farming
  • Hidden text, etc.
  • Gateway or Doorway pages
  • Cloaking
  • Keyword Stuffing



Question: What is PPC?
PPC stands for Pay Per Click and is an advertisement campaign hosted by Google.


Question: What are Webmaster tools?
Webmaster tool is a service provided by Google from where you can get backlink information, crawl errors, search queries, Indexing data, CTR, submit Sitemap etc.


Question: What is the latest update in SEO?
  • Panda
  • Penguin



Question: What is cross linking?
In simple way cross linking means referral links whenever we post content from other website for our users and reader and in return place the referral link of the website is called cross linking.


Question: How will you resolve canonicalization issue?
I will resolve canonicalization via using .htaccess file.
it happens several time that the home page of website have different urls like:

http://www.example.com/,
http/www.example.com/index.html or http://example.com/

with use of .htaccess i will keep only URL of above. If someone open another URL, that will be automatic redirect to kept URL.


Question: What is Pagination in SEO?
Pagination is used to send the user to another page of same website. For Example, if you search something it will it number of page which have same type of data. Now you can decided which page to visit.


Question: Who is Matt Cutts?
Matt Cutts is the head of Google's web spam team.




Friday 12 December 2014

Wordpress Interview Questions and Answers

Wordpress Interview Questions and Answers

Wordpress is opensource content management system where you can add/update/delete contents from admin section. Content may be text, images or videos etc. 

Because it is opensource, so you can update the code at free of cost. Wordpress built on PHP/MySQL/javascript (which is also an Open Source) and licensed under GPL. You can create different types of websites whether it is personal / commercial website. Today most of developer prefer wordpress as its easy to install and millions of plugins, themes are available over internet at free of cost & you can do customization.  




Question: What is Wordpress?
Wordpress is Content Management System which have robust admin section. From Admin section you can manage the website text/html, image & videos etc. You can easily manage pages & posts. You can set meta title, meta description & meta keywords for each post. It gives you full control over post & pages .



Question: Is Wordpress opensource?
Yes, Wordpress is opensource and you can do customization as per your requirement. Wordpress is built in PHP/MySql/javascript/jQuery which is also an opensource.



Question: What is current stable version of wordpress?
4.1 released in November 20, 2014



Question: What kind of website can I build with WordPress?
WordPress was originally developed as a blogging in 2003 but now it has been changed a lot. you can create personal website as well as commercial website.
Following types of websites can be built in wordpress:
  • Informative Website
  • Personal Website
  • Photo Gallery
  • Business Website
  • E-Commerce website
  • Blogging
Today, million of free/paid wordpress themes, wordpress plugin are available which help you to create as per your requirement.



Question: From where you can download plugins?
https://wordpress.org/plugins/



Question: From where you can download themes?
https://wordpress.org/themes/



Question: What is Hooks in wordpress?
Hooks allow user to create WordPress theme or plugin with shortcode without changing the original files.



Question: What are the types of hooks in WordPress?
Following are two types of hooks
A) Action hooks: This hooks allow you to insert an additional code.
B) Filter hooks: Filter hooks will only allow you to add a content or text at the end of the post.



Question: What are positive aspects of wordpress?
  • Easy to install and upgrade the wordpress
  • In-built SEO engine and you can manage the URL and meta data as per your requirement.
  • Easy to themes and plugins
  • Multilingual available in more than 70 languages
  • Can be do customization as per requirement
  • Lots of free/paid themes/plugin available




Question: What is the default prefix of wordpress tables?
wp_ is the prefix for wordpress but you can change at the time of installation.



Question: What is WordPress loop?
The Loop is PHP code used by WordPress to display posts.



Question: What are the template tags in WordPress?
Template tags is a code that instructs WordPress to "do" or "get" something



Question: What are meta tags in wordpress?
Meta-tags are keywords and description used to display website.



Question: How to secure your wordpress website?
  • Install security plug-ins like WP security
  • Change password of super admin OR other admin
  • Add security level checks at server level like folder/file permission.



Question: How many tables a default WordPress will have?
Following are main table in wordpress:
  • wp_commentmeta
  • wp_comments
  • wp_links
  • wp_options
  • wp_postmeta
  • wp_posts
  • wp_terms
  • wp_term_relationships
  • wp_term_taxonomy
  • wp_usermeta
  • wp_users



Question: How to hide the top admin bar at the frontend in WordPress?
Add following code functions.php
add_filter('show_admin_bar', '__return_false');



Question: How to hide Directory Browsing in WordPress from server?
Add following code in htaccess file
Options -Indexes



Question: How to display custom field in wordpress?
echo get_post_meta($post->ID, 'keyName', true); 



Question: How to run database Query in WordPress?
$wpdb->query("select * from $wpdb->posts   where ID>10 ");



Question: What types of hooks in wordpress is used?
1)Following are Actions hooks:.
has_action()
add_action()
do_action()
do_action_ref_array()
did_action()
remove_action()
remove_all_actions()

2)Following are Filters hooks .
has_filter()
add_filter()
apply_filters()
apply_filters_ref_array()
current_filter()
remove_filter()
remove_all_filters()



Question: How can you backup your WordPress content?
WordPress admin -> Tools -> Import



Question: List most commonly functions used in wordpress?
  • wp_nav_menu() :- Displays a navigation menu.
  • is_page() :- to check if this is page OR NOT, will return boolean value.
  • get_the_excerpt() :- Copy the excerpt of the post into a specified variable.
  • in_category() :- Check if the specified post is assigned to any of the specified categories OR not.
  • the_title():- Displays the title of the post in website.
  • the_content():- Displays the contents of the post in website.



Question: What are the file structure in wordpress.
Following are main files which used in wordpress
  • index.php :- for index page.
  • search.php :- For display the search result page.
  • single.php :- for single post page.
  • page.php :- display the static pages.
  • category.php :- Display the category page.
  • tag.php :- For display the tags page.
  • author.php :- For display author page.
  • taxonomy.php :- For display the taxonomy archive.
  • attachment.php :- For managing the single attachments page.
  • header.php :- For managing top part of page.
  • footer.php :- For manage bottom part of pages.
  • archive.php :- For archive page display.
  • 404.php :- For display 404 error page.

Friday 3 October 2014

Difference Between Hadoop and Big-Data

Difference Between Hadoop and Big-Data


Big data is a term, everything where you stored lots of data which is unstructured is bigdata. For example computer hard drive where we put movies, songs, excel file, doc file, application file and reports in just one folder.

Big data is simply the large sets of data that business person and other parties put together to serve specific goals and operations. Big data can include many different kinds of data in many different kinds of formats.

Big data is just a storage system where we stored millons of millions files.




Hadoop: It is open-source software framework for storage and large-scale processing of data-sets based on mapReduce. MapReduce splits big Data over several nodes in order to achieve a parallel computing.

Hadoop is software program which works on big data to provide you useful information.

Hadoop is just a software which filter the required information from tons of information.

Hadoop Interview Questions And Answers



Monday 22 September 2014

Memcached interview questions and answers

Memcached interview questions and answers

What is Memcached?
It is component which stored the data temporary for 1 Hour/ 6 Hour/1 Day etc. When we integrate the Memcached with our application, performance of application increased.
OR
Memcached is open source, high-performance distributed memory object used for caching so that execution can be enhanced at nth level.



How Memcached Works?
  • Try to get to get the detail of user, Browser send the request to application.
  • Application call the Memcached for particular user.
  • If Result found in Memcached, Return the result from Memcached.
  • If Result Not found in Not Memcached, Application send the request to database and save the result in memcached.
  • Each Memcached have one unique key.
  • Get/Set the data works on the behalf of key.
  • you can also delete one or more keys.
  • You can also assign tags to one/more keys.



Who is Author of Memcached?
Danga Interactive


In which Language Memcached is Written?
'C' Language


What is offical website of Nginx?
http://www.memcached.org/


When Memcached's initial version launched?
May 22, 2003




What is the Best Usage of Memcached?
  • Easy to install in windows as well as in unix system.
  • it offers API integration for all the major languages like Java, PHP, C/C++, Python, Ruby, Perl etc
  • Improve the performance of web application by caching
  • Reduce the burden of Db server
  • You can delete one/more values.
  • you can update the values of keys.
  • You can use use "Tags" for keys.



How to install Memcached?
Click Here


Memcached Commands
Connecting to Memcached server with telnet Command?
telnet hostName portNumber


How to get the value of key?
get key


How to set the value of Key?
set key 0 900 4
Format: set [key] [flags] [exptim] [bytes] [noreply]


How to add the value in Key?
add key 0 900 4
Format: add [key] [flags] [exptim] [bytes] [noreply]


How to replace the value of Key?
replace key 0 900 4
Format: replace [key] [flags] [exptim] [bytes] [noreply]


How to append the value of Key?
append key 0 900 4
Format: append [key] [flags] [exptim] [bytes] [noreply]


How to prepend the value of Key?
prepend key 0 900 4
Format: prepend [key] [flags] [exptim] [bytes] [noreply]


How to delete the Key?
delete key 


How to show the Stats?
stats


How to get the Version?
Version


How to close the connection?
quit

Wednesday 17 September 2014

UNIX Commands Interview Questions and Answers

UNIX Commands Interview Questions and Answers

Question: How to create readonly file?
touch fileName.txt
chmod 400 fileName.txt


Question: How to get the OS in unix?
uname -a


Question: How do you know if a remote host is alive or not?
ping www.example.com
telnet www.example.com


Question: How to copy from one host to another host?
scp file.zip username@hostname:/foldername


Question: How do you find which process is taking how much CPU?
top


Question: How do you check how much space left in current drive
dh-h

Question: How to Restart Apache over the SSH?

/etc/init.d/apache2 restart


Question: How to Stop Apache over the SSH?

/etc/init.d/apache2 stop


Question: How to Start Apache over the SSH?

/etc/init.d/apache2 start


Question: How to Restart Httpd over the SSH?

service httpd restart


Question: How to Stop Httpd over the SSH?

service httpd stop


Question: How to Start Httpd over the SSH?

service httpd start


Question: Import database from sql file to mysql?

mysql –u username –p databasename tablename < sqlfilename.sql


Question: How to delete ALL files including sub directory in current directory with prompting each time?

rm –r *


Question: How to display first 7 lines of file?

head -7 fileName.txt


Question: How to display Last 7 lines of file?

head -7 fileName.txt


Question: How to reverse a string in unix?

echo "Web technology expert notes" | rev


Question: How to unzip a file in Linux?

unzip –j file.zip


Question: How to test if a zip file is corrupted in Linux?
unzip –t file.zip


Question: How to find hidden files in current directory?
ls -lrta


Question: How to check if a file is zipped in Unix?
file file.txt //file.txt: ASCII text


Question: How to check all the running processes in Unix?
ps –ef


Question: find all files in current and subdirectories which contains 'webtechnology' name?
find . -name 'webtechnology'


Question: How to make any script file executable?
chmod 755 *.sh


Question: How to kill process in unix server?
kill -9 #pid

Friday 12 September 2014

PHP Technical Interview Questions and Answers

PHP Technical Interview Questions and Answers

How can we get the browser properties using PHP?
echo $_SERVER['HTTP_USER_AGENT'];
$browser=get_browser(null,true);
print_r($browser);


How can we register the variables into a session?
session_register($sessionVar);


How can we know the total number of elements of Array?
sizeof($arrayVarriable);
count($arrayVarriable);


How can we create a database using php?
mysql_create_db('database_name');


What are encryption functions in PHP?
CRYPT(), MD5()


How to store the uploaded file to the final location?
$fileName = $_FILES["uploaded_file"]["name"]; 
$fileTmpLoc = $_FILES["uploaded_file"]["tmp_name"];

// Path and file name
$pathAndName = "uploads/".$fileName;

// Run the move_uploaded_file() function here
$moveResult = move_uploaded_file($fileTmpLoc, $pathAndName);
// Evaluate the value returned from the function if needed
if ($moveResult == true) {
    echo "File has been moved from $fileTmpLoc  to $pathAndName";
} else {
     echo "ERROR: File not uploaded successfully";
}


How to get Mysql Error while executing query through mysql_query?
$data = mysql_query("SELECT * FROM users");
if(IS_NULL($data)){
echo mysql_error();
}


How do you call a constructor for a parent class?
parent::constructor()


How to get full date with php using date function?
echo date('Y-m-d H:i:s'); //2014-09-12 20:08:05


What are the Formatting and Printing Strings available in PHP?
printf() Displays a formatted string
sprintf() Return a formatted string in a variable
fprintf() Prints a formatted string to a file
number_format() Formats numbers as strings


How can we find the number of rows in a result set using PHP?
$obj = mysql_fetch_obj(mysql_query("select count(*) as total from users"));
echo $obj->total;


Which is the latest version of PHP?
The latest stable version of PHP is 5.5.14 released at 27 June 2014 .


How we expire cookie?
setcookie($cookieName,$cookieValue,time()-60*60*60*24); //Just set the previous time


What is use of var_dump?
It gives the value of Boolean/ text / Array/Object with data type.


What is final class?
Once declared any class as final class, we can't override it in future.


How many types of errors in PHP?
  • Notice error
  • Warning error
  • Fatal error


What is a .htacces file?
.htaccess is a configuration file running on Apache server.


Is PHP compiler language?
No, It is interpreted Language.


What are web services in PHP?
Web services are the server which is used to store, process and deliver web pages to clients(Browsers like mozilla, IE, Chrome etc).


How can we change the time zones using PHP?
date_default_timezone_set('America/Los_Angeles');


What are access modifiers in php?
public,protected and private are the three types of access modifiers in php.




How can we destroy a session in PHP?
session_destroy();


What are default session time and path? Default session time in PHP is 1440 seconds(24 minutes). Default session save path id temporary folder i.e tmp


What is the syntax to send a mail in PHP?
mail ($to , $subject ,$message ,$headers, $parameters);


Give an example of ternary operator in PHP?
echo ($age >18) ? 'Matured' : 'Not Matured' ;



Thursday 11 September 2014

CSS Interview Questions and Answers

Cascading Style Sheets is a style sheet language used for formatting of a html pages in websites. While most often used to style web pages and user interfaces written in HTML and XHTML, the language can be applied to any kind of XML document, including plain XML, SVG and XUL. CSS is a cornerstone specification of the web, and almost all web pages use CSS style sheets to describe their presentation.

In all website, we used css to design the website. It always help a lot to look better our website. There are lot of tutorials online to learn the CSS in easy steps. To learn CSS you need not install anythings, just need a Browser (mozilla, firefox etc )  to display the page and Editor (Net beans, Notepad++) to edit the css file.



What is class in CSS and why we use?
Class is basically used for grouping the attributes for applying same css.
To apply the same type of styles on multiple tags, we add the class on the tags.
then we add the styles on same class in css file.


What is grouping?
Grouping is gathering  into a comma separated list two or more selectors that share the same style or (2) into a semicolon separated list two or more declarations that are attached to the same selector.


Is CSS case sensitive?
Cascading Style Sheets (CSS) is not case sensitive.


What is CLASS selector?
Class selector is a "stand alone" class to which a specific style is declared. Using the CLASS attribute the declared style can then be associated with any HTML element. The class selectors are created by a period followed by the class's name. The name can contain characters a-z, A-Z, digits 0-9, period, hyphen, escaped characters, Unicode characters 161-255, as well as any Unicode character as a numeric code, however, they cannot start with a dash or a digit


What is cascade? 
Cascade is a method of defining the weight (importance) of individual styling rules thus allowing conflicting rules to be sorted out should such rules apply to the same selector.


What are different ways to integrate a CSS into a Website?
Following are 3 simple ways
Inline: Use STYLE attribute in the tags.
Embedded: By placing the code in a STYLE element within the HEAD element.
Linked/ Imported: Place the CSS in an external file and link it via a link element.


Explain external Style Sheet? How would you link to it to web page?
Create a CSS file and place all the CSS in that file and include the same file in one OR more web pages called External Style Sheet?
<link rel="stylesheet" href="/css" />


What are the advantages and disadvantages of External Style Sheets?
Advantages of External Style Sheets are:
  • Using them, the styles of multiple documents can be controlled from one file. 
  • Classes can be created for use on multiple HTML element types. 
  • In complex situations, selector and grouping methods can be used to apply styles. 
  • If you need to update the css file in live site, then need not to upload all files. You can just upload the css file.
  • It is easy to manage Files
Disadvantages of External Style Sheets:
  • In order to import style information for each document, an extra download is needed. 
  • Until the external style sheet is loaded, it may not be possible to render the document. 
  • For small number of style definitions, it is not viable.
Recommendation: Always use External Style sheet



What are the advantages and disadvantages of Embedded Style Sheets
Advantages of Inline Styles
  • It is especially useful for small number of style definitions. 
  • It has the ability to override other style specification methods at the local level(in one place). 
Disadvantages of Inline Styles
  • It does not separate out the style information from content. 
  • The styles for many documents can not be controlled from one source. 
  • Selector grouping methods can not be used to handle complex situations. 
  • Control classes can not be created to control multiple element types within the document.
  • Good Companines never allowed to use Inline css in website
Recommendation: Never use In-line Style sheet


What is CSS selector?
A CSS selector is the part of a CSS rule set that actually selects the content you want to style. Let's look at all the different kinds of selectors available.
Universal Selector: Apply CSS on all elements
* {
   color: red;
}

Element Type Selector: Apply CSS on particular attribute
ul {
   color: red;
}

ID Selector: Apply css which have same ID
#attributeId {
   color: red;
}

Class Selector: Apply CSS which have same Class
.box {   
   color: red;
}

Descendant Combinator: Apply Css where we have Combine two or more selectors so you can be more specific in your selection method.
#container .box {   
    color: red;
}

Child Combinator: Apply CSS to the child
#container > .box {
   color: red;
}

General Sibling Combinator: Apply CSS based on Sibling
h2 ~ p {
   color: red;
}

Adjacent Sibling Combinator: Apply CSS based on adjacent sibling
p + p {
     color: red;
}

Attribute Selector: Apply CSS on particular tag with having same attribute.
input[type="text"] {
      color: red; 
}

Pseudo-class: Apply CSS on the class which does not exist in real.
a:hover {
   color: red;
}


What is Tweening?
Tweening is used in animations, it is the process of generating intermediate frames between two images.
It gives the impression that the first image has smoothly evolved into the second one.


Explain RWD?
RWD is the abbreviation for Responsive web design.
In this technique, the designed page is perfectly displayed on every screen size and device, be it desktop, mobile, laptop or any other device. You don’t need to create a different page for each device


What is the use of CSS sprites?
A web page with large number of images takes a longer time to load in the website, because image separately sends out a http request.
The concept of CSS sprite helps in reducing this loading time for a web page by combining various small images into one image. This reduces the numbers of http request.


How to import CSS?
import url('/css/typography.css');


What is Contextual Selector?
It is a string of individual selectors separated by white space, where only last element in the pattern is addressed.


What are Pseudo Classes?
Pseudo classes allow you to identify HTML elements on characteristics. These are specified using a colon to separate the element name and pseudo class.
Following are Pseudo Class example:
a:link {font-color: red;}
a:visited {font-color: green;}
a:hover {font-color: yellow;}


What are some ways you might target IE (or IE6) only, without affecting other browsers?
<!--[if IE 6]>
<link rel="stylesheet" type="text/css" href="ie6.css" />
<![endif]-->


What does z-index do?
The z-index property specifies the stack order of an element. An element with greater stack order is always in front of an element with a lower stack order.



What is Media Query?
It is added in CSS3. A Media Query consists of a media type and at least one expression that limits the style sheets' scope by using media features, such as width, height, and color.

[link rel="stylesheet" media="(max-width: 800px)" href="example.css" />]

@media (max-width: 600px) {
  .facet_sidebar {
    display: none;
  }
}