Dunno if this helps. This is a dictionary term, that leans more in the direction of desktop programming.
To transform a program written in a high-level programming language from source code into object code. Programmers write programs in a form called source code. Source code must go through several steps before it becomes an executable program. The first step is to pass the source code through a compiler, which translates the high-level language instructions into object code.
The final step in producing an executable program -- after the compiler has produced object code -- is to pass the object code through a linker. The linker combines modules and gives real values to all symbolic addresses, thereby producing machine code.
Generally when one speaks of compiling PHP, the context is in terms of taking the source code for PHP itself ("Complete Source Code" on the PHP download page) and running a series of programs from the command line to create the PHP executable. That process of going from raw source code into an executable/binary program is compilation. The compiled program (php on linux/unix, php.exe on windows) is what interprets/runs all of our PHP code.
Are you looking to compile PHP yourself, or just looking to see what it's about because you didn't understand the meaning?
Not true, the server compiles it to a binary then runs it. It has to, the processor does not understand PHP.
So as I said you write it, up load it to the server and it runs.
Because YOU don't compile it. The server does so, but only when requested to run it. A separate compiled version doesn't exist (except in memory), unlike with C. Glad we agree on that.