How Multi-threading is important in JAVA

Running more than one task concurrently is called multitasking. All the tasks will be executed by CPU. Even though it looks more than one task at a time, but practically its not possible. CPU can execute only one task at a time.

As a user of computer we can observe multiple programs running on computer which is happening because of Operating System CPU Scheduling Algorithm.

Some of the famous Algorithm's implemented successfully is

1. First Come First Serve.

2. Round Robin.

3. Shortest Job First.

4. Priority Based.

5. Non - preemptive.

The task of all these algorithm is switching the CPU from one task to other task. I can also put in this way that is allocating the CPU time for all the tasks which have been started.

Two types are

1. Process Based.

2. Thread Based.

Process is nothing but a program. Process based is nothing but running multiple programs concurrently. Every program will have its own memory space. Communication between programs , data sharing are too expensive in process based multitasking.

Thread Based is very interesting. Thread is nothing but a part of program. In other words running different parts of same program concurrently.

All threads will share the same memory space. Memory will not be allocated separately for each threads. Data sharing, context switching, communication between programs is inexpensive compared to process based multitasking.