The document discusses system software and different types of loaders. It defines system software as programs that support computer operation systems like operating systems, compilers, and databases. Loaders are system programs that load object programs into memory and execute them. There are different types of loaders including absolute loaders that load code to specific addresses, bootstrap loaders that load the initial operating system, and relocating loaders that can load code to any available memory locations. Relocating loaders allow for more efficient sharing of memory and use of subroutine libraries when running multiple programs.