How to compile source code...
 

If i download say the source code for Apache, how do i compile that into an executable?

is it a simple use of commands or are more difficult ways used?

Normally it´s:
./configure
make
make install

(make install should be executed as root).
But it can be different for apache, there should be a readme or install document in the download.

ahhhh...thats the way i installed samba but i never realised i had compiled it from source code!

so that compiles it AND installs it?

./configure configures it for your system?

----------
make
make install
these two actually compile and install it???

That's pretty much the jist of it. Configure, then make compiles and make install installs it. You can use different options with configure to put things in different directories and so forth also, if that's something you need. But defaults are almost always fine.