4.1 Types of software and interrupts

By the end of this section you should be able to

• 4.1.1 Compare system software and application software
• 4.1.2 Describe the functions of an operating system
• 4.1.3 Explain how hardware, firmware and the OS run applications
• 4.1.4 Describe how interrupts are generated and handled

Lessons

1. System and application software
2. Operating systems and user interfaces
3. How the operating system manages the computer
4. Interrupts

Key vocabulary

System software

Software that provides the services the computer needs, e.g. the operating system and utilities.

Application software

Software that provides the services the user needs.

Operating system

Manages files, memory, peripherals, multitasking, security and user accounts, and provides an interface.

Utility software

System software that helps maintain the computer.

Firmware

Software stored permanently on hardware, such as the bootloader.

Interrupt

A signal that tells the CPU something needs its attention.

Interrupt service routine (ISR)

The code that runs to handle a particular interrupt.