The Raspberry Pi is a Credit card sized single-board microcomputer. Developed in the United Kingdom by the Raspberry Pi Foundation. It's main purpose was to given perspective programmers a starting off point. It runs a variant of Debian Linux known as Raspian, and is uses Python and Scratch as entry-level programming environments.
The Pi features a 700 MHz processor, 256 MB of RAM, HDMI out, composite video out, 3.5mm audio jack out, and USB 2.0. The model B bumps the RAM to 512 MB, adds an ethernet port, and a second USB 2.0 port.
Get familiar with a Pi and start programming!
Raspberry Pi is a trademark of the Raspberry Pi Foundation.