Final answer:
A Time-sharing system is a computer system that allows multiple users to run programs simultaneously by giving each user a small slice of time in rapid succession.
Step-by-step explanation:
A computer system that permits multiple users to run programs at the same time is known as a Time-sharing system. This system allows many users to share the computer resources simultaneously by providing a small slice of time to each user's program in rapid succession. Different from Real-time systems which are used for systems that require responses in a guaranteed time, Multi-programming systems which maintain several programs in memory simultaneously for execution, and Multi-tasking systems often referring to a single user running multiple programs concurrently, the key characteristic of time-sharing systems is their ability to allow multiple users to interact with the computer at the same time.