What is UNIX?
In short, UNIX is a type of operating system. It actually predates most modern operating systems such as Windows, Android, Linux, etc. In fact, operating systems such as BSD, Linuz, and Apple OS have developed from UNIX, or at least have been heavily influenced by it. UNIX was developed in the 1970s at the Bell Labs research center by Ken Thompson, Dennis Ritchie, and others.
UNIX is primarily known for its multitasking and multiuser compatibility. UNIX was designed to be portable, multi-tasking and multi-user in a time-sharing configuration. It is also characterized by some concepts such as the use of plain text for storing data, as well as a hierarchical file system and the use of a large number of software tools. It is also known for the way it treats devices and certain types of inter-process communication (IPC) as files. In UNIX, small programs can be strung together through a command-line interpreter using pipes, as opposed to using a single monolithic program. These concepts together are collectively known as the "Unix philosophy".