Is there any real difference between a compiler and an assembler?
An assembler translates assembly code to machine code. The translation is mechanical, and can be done in only one way. In contrast, a compiler has more freedom when it compiles the relevant programming language - it can optimize, for example, and even non-optimizing compilers produce different code. Also, compilers can be written in a way that separates the "front-end" (corresponding to the programming language) and the "back-end" (corresponding to the computer architecture), whereas with assemblers the two are always the same.