compilers

how do compilers work ?
i mean when you have say c or c++ code or lisp program, how does it turn it into machine code ?
isnt it too complicated and take a lot of machine code ?
or like scheme tail loop, how is it done . its hard to convert just one loop
or like c++ classes theres no clases in machine assmebly
i dont understand

thanks

>>28
I am a database and all I do is aim to please.
Funny, I always heard this line as ``I am a database and all I do is ENTERPRISE''