Linux is an open-source operating system that is based on Unix. It was created by Linus Torvalds in 1991 and has since become one of the most widely used operating systems in the world. Linux is known for its stability, security, and flexibility, making it an ideal choice for a wide range of applications, from personal computers to enterprise-level servers. One of the key features of Linux is that it is open source, which means that its source code is freely available for anyone to access, modify, and distribute.