The obvious advantage of laptops is their small form factor. Often called notebooks, laptops typically house the machine's hardware in a small base no more than a couple of inches in height. The monitor is attached to the base, making the computer one piece of equipment. With their small size and the absence of additional components like an external monitor, laptops are designed for portability. While they do not offer nearly as many expansion or upgrade options as desktops, you can usually upgrade integral components like memory, battery and hard drive. Laptops typically have screens between 14 and 18 inches.