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.
Thinkstock Images/Comstock/Getty Images. The universal serial bus (USB) enables users to connect plug-and-play devices to a PC, but different kinds of USB exist. USB 1.0 and 1.1 are older versions of the interface that are much slower than the newer USB 2.0 and 3.0 releases.