Computers are designed for human use. People use computers to solve various problems. The computer processes the input data provided by humans and gives the results or output. That's why communication between computers and humans is so important. This interaction is called human-computer interaction (HCI) . The easier this interaction is, the more the computer can be used. So computer engineers and scientists are constantly trying to improve computer interaction. This has led to the emergence of different types of operating systems based on the working environment or interface.