A large company such as a retail store or airline reservation system uses a multi-user computer that acts as the central computer in a network.
<h3>Multi-user computer</h3>
A multi-user operating system (OS) is a computer system that allows multiple users from different computers to have access to a single system's OS resources at the same time.
A mainframe is a multi-user computer capable of connecting hundreds or thousands of users simultaneously. This are used by large companies.
