Assembling

An assembler translates assembly files into machine code in binary object files (usually .o on Unix, .obj on Windows).

Object code is hardware architecture and operating system specific.

Object file formats are file formats used for the storage of object code. They include:

• a.out: the original Unix object file format,
• Executable and Linkable Format (ELF).

Object files can be linked with other object files to generate a final executable or a library.