Batch processing is assembling a group of jobs or tasks and then doing them all in a batch. Usually something like printing a monthly bill for sending out to customers. Real-time processing is just that, processing calculations right now, in real time. Something like crediting payments to a person's monthly bill would be an example of real time processing. The payments are processed as they come in, on a first come, first served basis. Time sharing is also called time slicing. The CPU divides the number of clock cycles it has per second among several processes. This also goes by the name, multitasking, but that is a misnomer as the CPU only processes one instruction at a time. Think a multilane freeway and cars all merging to cross a river on a 1 lane bridge. Distributed processing means more than one CPU working in parallel. In the freeway analogy, think 1 lane from the freeway splitting and using more than one bridge across the river. The load is distributed over two or more bridges. All of these are just various ways and means of accomplishing one or more tasks from a group of one or more tasks.