What is decodeURI(), encodeURI() in javascript?

what is the use of these function...

Hi Naveen,

Many characters cannot be sent in a URL, but must be converted to their hex encoding. These functions are used to convert an
entire URI (a superset of URL) to and from a format that can be sent via a URI.

Here is an example:

<script type="text/javascript">

var test1="http://www.google.com/search?q=sonofusion Taleyarkhan";

document.write(encodeURI(test1)+ "<br />");
document.write(decodeURI(test1));

</script>

Output :

http://www.google.com/search?q=sonofusion%20Taleyarkhan
http://www.google.com/search?q=sonofusion Taleyarkhan