For questions about or involving the open-source operating system modelled on UNIX. Use this tag only when your question is about Computer Networking where Linux is used as a network bridge or router.
This tag is only suitable for questions where Linux is a network device, for instance, as a bridge or router. All questions about Operating system and/or computer/server configurations or installations are explicitly off topic. Use of applications not generally considered to be tools used by network professionals are also off topic.
Linux is an open source operating system just like Windows or macOS. It has been around since the mid 90's and is broadly used on a big variety of devices. It both comes with a graphical interface or command line interface.
In a network perspective, many businesses uses Linux as a full blown firewall solution running the free open source pfSense software. Besides firewall Linux can be used for a lot of different services, for instance: Management systems, Syslog, Automation in network configurations and monitoring systems.