- Multiuser System: Computer able to concurrently and independently execute several apps belong to two or more users.
- Executing multiple programs at the same time will mean that the amount of processing power allocated to each program will be cut
- In addition there are delays in switching between processing between applications
- Important Features
- Authentication
- Protection against buggy programs causing other ones to crash
- Protection against malicious apps trying to access memory
- Limit resources assigned to each user