1. Interfaces

2. Peripheral devices connect to the CPU, via slots on the back of the computer.

3. Such devices include printers, scanners, digital cameras, digital video recorders, mice, keyboards etc. They also include mass storage devices such as magnetic tape drives and disk drives.

4. Each device has its own operational speed, uses its own code and deals with different amounts of data at a time.

5. In order for these devices to communicate with the CPU they need to be interfaced.
An interface is a unit that sits between the CPU and a peripheral device and compensates for the differences in speed, codes etc. to ensure compatibility.

6. Summary
An interface makes the link between the processor and a peripheral (disk drive, printer etc.).
Peripherals work at different speeds, use different formats.
Interface transfers data so the processor is delayed as little as possible. It has buffers to store blocks of data in transit.