Yes , WAMP is not server itself, it is a software package which has Apache,Mysql,PHP bundled in it.
You can run your php application with out using WAMP package, for that you need to install
PHP[
^],
Apache [
^]and
Mysql [
^]separately and integrate it, which can be tedious work sometimes.
This is what WAMP does it gives you everything ready to run your application on windows.
hope it helps :)