Linux is an open-source operating system kernel created in 1991 by Linus Torvalds, with distributions like Debian, Ubuntu built on top of the Linux kernel and GNU components. The Linux kernel and operating system provide many advantages like being free and open-source, allowing for customization and modification of the code, and being used widely as a server platform, by developers, and on desktop computers. While powerful and customizable, Linux distributions can also present some disadvantages like a learning curve for new users and less commercial software than Windows.