Raspberry Pi
The Raspberry Pi is a computer--except it doesn't have a hard drive, monitor, keyboard, mouse, CD/DVD drive, or even a case to house itself in. Roughly the size of a credit card, it stores its operating system programs, and files on an SD card. It has two USB ports for a mouse and keyboard, and it may be connected to a monitor via HDMI port. Originally intended to help spur student interest in computing, the low-cost Raspberry Pi can do most of the things you can do on any other much more expensive computer: web surfing, image editing, media playing, office applications, controlling appliances, and robotics and programming.
Additional resources on Computational Thinking and Coding are available HERE. This includes appropriate levels for students to explore a Raspberry Pi.
Resources