Callback is a function that is passed to another function as parameter and callback function is called inside another function.
Example:
Here following are callback function.
The trigger is code that is executed automatically on some events.
Example:
Handler: An event handler executes a part of a code based on certain events occurring within the application such as onClick, onBlur, onLoad etc.
Example:
Following are few more event handler
Example:
$("#MyButton").click(function(){
    $("p#hideDiv").hide("slow", function(){
        alert("function() is callback and called.");
    });
});
Here following are callback function.
function(){
        alert("function() is callback and called.");
    }
The trigger is code that is executed automatically on some events.
Example:
Handler: An event handler executes a part of a code based on certain events occurring within the application such as onClick, onBlur, onLoad etc.
Example:
$(document).ready(function(){
    $("button").click(function(){
        $("input").trigger("select");
    });
});
Following are few more event handler
| Event | Description | 
|---|---|
| onchange | An HTML element has been changed | 
| onclick | The user clicks an HTML element | 
| onmouseover | The user moves the mouse over an HTML element | 
| onmouseout | The user moves the mouse away from an HTML element | 
| onkeydown | The user pushes a keyboard key | 
| onload | The browser has finished loading the page | 

