PHP or JAVASCRIPT??

[abhishekphukan]

Do we need both server scripting like (PHP)and client scripting languages like (JAVASCRIPT) in building a website?..Is it a ""MUST LEARN SITUATION""....

I mean does both the langages related to each other ..or we can just learn one language and take that knowledge to build a website.Putting HTML and CSS aside.
Please can someone clearify my confusion in plain and in a simple way.Thank You..:)
I ll be waiting for the replies..

[Luuk]

PHP code is evaluated server-side
Javascript is evaluated client-side

If you want to check if some field of a form contains valid data, checking client-side will be faster, but will not change the need to do the checking server-side too.....

[Dormilich]

if you use Node.js, you could use JavaScript for both client-side and server-side coding …