Linux is an open source operating system created by Linus Torvalds. It is used widely for personal computers, file and print servers, internet service providers, and as the operating system for many websites. Some popular Linux distributions include Debian, Red Hat, Slackware, and SuSE. Installing Linux involves selecting options like language, partitioning disks, and software to install. Configuring involves setting the time, hardware, and creating user accounts.