# Module 6: Introduction This module introduces you to system security. A computer system is an integrated set of hardware components and software applications that work together to enable users to perform specific tasks or achieve specific goals. It typically consists of input devices such as keyboards, mice, scanners, etc.; output devices such as monitors, printers, plotters; a processor unit that executes the instructions of programs stored in memory; storage components for data and applications that can be quickly retrieved when needed; and network connections to enable communication between different systems. Depending on the application, a computer system can look very different. For example, if you think of your washing machine as a computer system, it consists of a (slow and cheap) processor, inputs (such as sensors and the buttons to select the programme), outputs (such as the display) and perhaps a network connection via USB or Wifi (yes, you can connect your washing machine to a computer). On the other hand, a web server is probably a completely different computer system. Finally, it is possible to think of a whole network of computers as a system. The integration and communication between different parts of a computer system can provide more functionality than a single component alone, and can also lead to different security issues than a single component. Each system therefore has its own unique characteristics and security issues that need to be addressed. As system security covers many issues that we've already discussed, there will not be a detailed discussion of system security.