To be able to perform several tasks at once, you must be able to multitask concurrently. Concurrent means existing or happening at the same time, which exactly describes the act of performing several tasks at once. Whereas multitasking reactively, describes doing things not at once but in response to what is happening around you. In the case of sequential multitasking, this would mean doing the tasks at once but following a logical order or sequence. While multitasking requires good thought process, problem solving and organization, it would be hard to complete multiple tasks by being reactive or attempting to do so sequentially.