Linux distributions, or "distros," are versions of the Linux operating system packaged with different software, tools, and configurations to meet various user needs. Each distribution includes the Linux kernel, system utilities, and additional software such as desktop environments or server tools. Popular Linux distributions include Ubuntu, known for user-friendliness; CentOS and Red Hat Enterprise Linux (RHEL), preferred for enterprise environments; Debian, valued for its stability; and Arch Linux, favored by advanced users for its customization. Linux distributions cater to a wide range of purposes, from desktop use to server management and embedded systems.