Laptop
A laptop is a computer that folds in half and is generally considered rather portable. The top half most often consists of a screen and the bottom half often consists of a keyboard and some sort of device to serve the function of the mouse. Screens can come in various sizes ranging from about 7 inches, probably all the way up to around 20 inches (measured diagonally).
They range in prices from around a couple hundred dollars to many of thousands. This is a very rough estimate. Groups have targeted prices of 100 dollars for a laptop, and even possibly 10 dollars.