Unix

Techopedia explains Unix

Unix was developed based on the philosophy that the power of the system comes from the relationships among programs, rather than on the programs themselves. Unix programs are written to do one thing well, and programs are written so that they work together. As such, Unix developers espouse simplicity, portability and clarity in design. In order to adhere to this philosophy, Unix systems are characterized by:

• The use of text files for data storage
• A hierarchical file system
• A large number of small programs, strung together through a command-line interpreter
• Use of shell scripts
• The avoidance of captive user interfaces

Unix had a significant impact on other operating systems and can be credited (in whole or in part) for the following:

• The use of high-level language in operating systems
• Hierarchical file systems
• Its syntax for regular expressions found widespread use
• Unix shell inspired many of the command line interpreters that followed
• C programming language became more ubiquitous
• Began the movement toward modularity and reusability in software engineering
• Helped contribute to the explosion of the Internet by making TCP/IP protocol more widely available
• Contributed to the launch of the free software movement

Free Unix-like operating systems such as Linux and BSD now hold a large portion of the market originally held by Unix.