What an operating system does, the utility software that keeps a computer running well, and how code reviews and audit trails make software robust.
What you will learn
- Describe the functions of an operating system
- Explain audit trails and code reviews
- Explain defragmentation, encryption, compression and backup utilities
- Tell system software from application software
The operating system
The operating system (OS) manages the hardware and runs the other software.
- User interface: a graphical user interface (GUI: windows, icons, menus and a pointer or touch), which is easy to learn, or a command line, which experts use for fast, powerful and scriptable jobs.
- Memory management: gives each program space in RAM, keeps programs apart and uses virtual memory when needed.
- Multitasking (process management): shares the CPU's time between programs so they seem to run at once.
- Peripheral management: uses device drivers to talk to printers, keyboards and other hardware.
- User management: creating accounts, checking usernames and passwords at log-on, and setting what each user may do.
- File management: organising files into folders, naming, saving, moving, copying and deleting them, and setting access rights such as read-only.
System software (the OS and utilities) runs the computer; application software does a task for the user.
The rest of this lesson and its 13 practice questions are locked.
In this lesson
- The operating system
- Utility software
- Robust software
- Try it: OS functions
13 practice questions, marked as you go; about 20 minutes in all.
Key terms
Operating system, Multitasking, Device drivers, System software, Application software, Defragmentation, Compression, Encryption, Backup, Full
In this unit: Computer systems
The CPU and the fetch-execute cycle step by step, what makes a CPU fast, RAM, ROM and virtual memory, secondary storage, and system software.