What is difference between Multithreading and miltiprocessing?

It is simple to understand. You question itself contains the answer. Only the keynote is: A single processor/core of the cpu can execute single task at a time, not more than one task. And you should be able to differentiate process and processor. process: is a task / small part of process processor: who performs the task (CPU) Assume you have two computer, one with dual/multi core (Ex: core2duo, dual core or quad core) processor and other with a old single core processor. And if you have a program which wants to perform two different operations / processes, you can go with multi core processor cpu to run the two tasks. What if you want to run these two operations on single core processor? You can run these two operations at a time with single core processor. Hence, running two processes/operations on different processors/cores is called as multi processing. You can also achieve multi processing with single CPU. When a processor/core of the cpu is waiting / idle, Operating system will take the control of the cpu and assigns the cpu to another process/operation. With multiprocessing there is an overhaed, i.e., CPU handling by operating system (formally known as context switch). assigning processor to processes, and taking back. What about Multithreading? Asume you have to complete two operations, with a single process? Just divide the process into multiple threads to complete different operations. As the entire process is inside the CPU, there won't be any overhaed/delay. In this case, Even if you have multi core cpu, only one core of the cpu will complete the two operations/threads. Program can contains multiple processes. Process can contain multiple threads. read less