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.
USB 2.0 is the standard port type. These days, mice, keyboards, hard drives, optical drives, printers, and just about anything else can be found in a USB 2.0 flavor to plug into one of these ports. Even with the emergence of USB 3.0 (SuperSpeed USB), USB 2.0 is still the most versatile connection.