1 Echocardiography (echo) is a painless test that uses sound waves to create pictures of your heart.  This test gives your doctor information about the size and shape of your heart and how well your heart's chambers and valves are working.
USB was designed to standardize the connection of computer peripherals (including keyboards, pointing devices, digital cameras, printers, portable media players, disk drives and network adapters) to personal computers, both to communicate and to supply electric power.
Techopedia explains Universal Serial Bus (USB) A Universal Serial Bus (USB) is basically a newer port that is used as a common interface to connect several different types of devices such as keyboards, printers, media devices, cameras, scanners, and mice. It is designed for easy installation, faster transfer rates, higher quality cabling and hot swapping.