In addition, UNIX was designed to respond to user behavior, there are many people at the same time. It is called multi concurrent users, and can work as many jobs at the same time, in a style known as multitasking.
In addition, Unix is designed to meet the user in a manner to multiple users at the same time called multiple-user. And can run multiple applications at the same time in a so-called multi-tasking.
The UNIX was designed to respond in a manner that a user has many people at the same time, called multi users and can work. Other jobs in the same time. In a style called multitasking.