The Universal Serial Bus is a very commonly used wired connection method. We usually use it to connect peripheral devices of all kinds to our computer. In the past, there was a wide range of methods for connecting peripherals. PS/2 was common for a mouse & keyboard, and the parallel port was used for printers, for example. Now, however, USB is used almost exclusively for these devices and the majority of other peripherals, such as webcams, scanners, good-quality audio peripherals, and external storage devices.
Advantages
Fast Data Transfer Speed - USB 3.0 can transfer 5Gbps. This would let you transfer an HD movie between an external HDD to your computer in seconds.
Connecting Multiple Peripherals - You can connect multiple peripherals to a single USB port. You can connect 127 different devices to a single USB port.
Provides Power to Device - USB provides power to the device you are connecting. This means you don’t need an additional power supply to many peripherals.
Highly Compatible with Devices - Pretty much every computer system has a USB port. USB 3.0 are even compatible with USB 2.0 ports (and vice versa).
Disdvantages
Short Range - USB has a relatively short range. The maximum practical length of USB 3.0 is just 3 metres.