Multi programming is the technique to run several programs at a time using "time sharing". The main concept behind the multiple programming is that an operating system stores many programs in the main memory simultaneously and then the processor takes one job from that job pool and it executed them. When that job have to wait for some input output then it takes another job from that pool and executes it.like wise it seems that it handles many programs at the same time.This is called 'Multi programming".
Whereas multi threading means the different threads in the process to perform similar type of the functions. Let's take one example that in the internet world server accepts the requests from the client side for the videos,audios,images. Now we consider the situation according to the single threaded system,in the busy network where many of the clients request for the same things the server would have provided its facilities to only one of the client.But this is not the case with multithreading .This problem is solved bu the multi threading.All the clients get the requested thing,eventhough it is same.But,we must consider the hardware and capacity of the server.Excessive load on the server for the same thing or different things might make the server crash.
