PHP vs Javascript

What are the similarities and differences between these two languages?

What i've gathered so far

They're both web based scripting languages.
PHP is an open source alternative to Microsoft's. It is a recursive acronym for PhpHypertextProcessing.

What i'd like to know is what can you do in JS but not in PHP and vice versa. Also, could Anusymous be written in JS ?

Javascript is not a serious language! Little can be done with it because it is slow! It is manly used for little things on websites which are done client side like HTML! Only a troll would even think Javascript is better than PHP!