A computer system that permits multiple users to run programs at the same time is called which?

• A. Real time system
• B. Multi tasking system
• C. Time sharing system
• D. Multi programming system

Answer: (B)

Time sharing is what this item is getting at: a computer system that lets several users run programs at the same time by rapidly switching the CPU between their sessions. This quick back-and-forth creates the illusion of concurrent usage and gives each user an interactive experience. Multi-tasking, while it involves running several programs at once, can occur within a single user’s session and doesn’t by itself guarantee multiple users. Real-time systems are built around meeting strict timing guarantees for critical tasks, not about supporting multiple users simultaneously. Multiprogramming keeps several programs ready to run to keep the CPU busy, but it focuses on efficient CPU utilization rather than multi-user interactivity. Therefore, the time-sharing concept best fits the scenario.