CUPS, or Common Unix Printing System, is an open-source printing system used on Unix-like operating systems, including Linux and macOS. It enables a computer to act as a print server, managing print jobs and queues for both local and network printers. CUPS uses the Internet Printing Protocol (IPP) as its basis, allowing standardized communication between computers and printers. With a web-based interface and support for a wide range of printer drivers, CUPS simplifies printer management and configuration. It is widely adopted due to its flexibility, scalability, and compatibility with various printer models and network environments.