Multitasking is a way of executing multiple tasks during the same period of time. Multiple tasks use common resources like CPU and main memory.
With a single CPU only one task can be running at one point of time, so CPU uses context switching to perform multitasking. Context switch (Context means state) is the process of storing and restoring the state of a process so that execution can be resumed from the same point at a later time.
Types of Multitasking:
Multiprocessing is a type of multitasking based upon processes i.e. context switching is done in-between processes. For example: Typing in notepad, Listening music and downloading file from internet at the same time. Here in example we can clearly see that all applications are independent. Multiprocessing is the type of multitasking which is handled at operating system level.
A process has a self-contained execution environment i.e. allocates separate memory area. Context switch time is more in case of processes because switch is done between different memory areas.
Multithreading is a type of multitasking based upon threads i.e. context switching is done in-between threads. In case of multithreading, multiple independent tasks are executed simultaneously. These independent tasks are the part of same application. Multithreading is the type of multitasking which is handled at program level.
A thread is a lightweight process. Thread uses process’s execution environment i.e. memory area. Context switch time is less in case of threads because switch is done within the same process’s memory area.
A thread represents a flow of execution. Every thread has a job associated with it.
Note: A thread can’t be exist without process, it exist within the process.
Difference between process and thread in java:
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