What is chain-loading (with reference to booting) ?

The chain loading is the type of method which is used by the computer program for replacing the current execution program with the new program in the system with reference to the booting.

It basically use the common data place for passing the information from existing to new program in the computer programming system. The chain loading does not support multi booting operating system.

The grand unified boot loader (GRUB) basically support both the chain loading and direct loading boot in the operating system.