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Knowledge organisers / Operating Systems

The purpose and functionality of operating systems: Memory management and multitasking

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Knowledge organiser

Operating Systems

1.5.1a.ii

What you need to know

The OS manages memory by allocating sections of RAM to different programs and tracking which parts are in use. Multitasking allows multiple programs to run seemingly simultaneously.

Key points

  • Definition:Memory Management: the OS allocates sections of RAM to programs, tracks what is in use, and frees memory when programs close.
  • Definition:Multitasking: running more than one program at the same time by rapidly switching between tasks, giving each a small slice of processor time.
  • When programs close, their RAM space is freed and overwritten by other tasks.
  • The OS ensures programs get the memory and processing time they need without interfering with each other.
  • Exam Tip:Multitasking does not mean programs truly run simultaneously on a single core — the OS switches between them so fast it APPEARS simultaneous.