Object Files

Comes in 3 flavors:
- Relocatable Object Files: Can be combined at compile time with Static Linker to create Executable Object Files
- Executable Object Files: Contains binary code and data in form that can be directly copied into memory and executed.
- Shared Object File: Special type of Relocatable Object Files that can be loaded at into memory and linked dynamically at load or run time.
Compilers and Assembler generate Relocatable Object Files and Shared Object File and linkers generate object files.
Technically, an object module is a sequence of bytes, and an object file is an object module stored on disk in a file.
-Object file formatting for various OS:
- Windows: Portable Executable (PE)
- Mac OS-X uses Mach-0 format
- And Linux systems uses Executable and Linkable Format(ELF).

NOTE: Memory resident code means stuff that always lives int the RAM, like kernel which is the memory resident part of the operating system.