USB

From Grokdoc

USB (which stands for "Universal Serial Bus" if you're into trivia) is a way of connecting things like keyboards, mice, digital cameras, etc. to your computer. The connector for USB is generally a small rectangle with square corners (another way of connecting devices, called Firewire, has a rectangle with two angled corners). In general, your keyboard and mouse are either USB or PS/2. If the connector is rectangular, you have USB. If it's round, you have PS/2.