The document discusses the Raspberry Pi, a credit card-sized computer. It provides an introduction to the Raspberry Pi, describing its low cost of $35 and support by the University of Cambridge. The document outlines the Raspberry Pi's hardware components and various models released over time. It also discusses how the Raspberry Pi works, including connecting peripherals like a keyboard, mouse, monitor, and installing an operating system from a microSD card. The document concludes with some applications of the Raspberry Pi like programming, gaming, robotics, and its use in education.