What is multi tasking ? Diff b/w process based and thread based multi tasking

Multi tasking: Executing several tasks simultaneously. Multi tasking has 2 types:
a) Process based Multi tasking

b) Thread based Multi tasking

Process based multi tasking: Executing several several tasks simultaneously where each task is a separate independent process.It is based on Operating System level.

Ex: a) writing java program in the editor b) watching youtube

Thread based multi tasking: Executing several several tasks simultaneously where each task is a separate independent part/thread of the same program.It is based on program level.