Capacity

Computer Science: Cambridge International GCSE, topic 1.1.7

Units of Capacity

The capacity of a device is how much data it can store. It is important to know the units of capacity so that we can compare the capacity of different devices.

The bit

The bit

  • The smallest unit of data that we can store is called a binary digit, or a bit for short.
  • The value of a bit can be either a 0 or a 1.
Grouping bits

Grouping bits

  • Because a bit is so small, we do not usually use it to measure data.
  • Instead, we group bits into larger groups such as:
  • Nibble (4 bits).
  • Byte (8 bits).
Common data units

Common data units

  • In reality, we need much larger groups than this to compare modern storage devices.
  • Common units are:
  • Kilobyte (KB) (1000 bytes).
  • Megabyte (MB) (1000 KB).
  • Gigabyte (GB) (1000 MB).
  • Terabyte (TB) (1000 GB).

Test yourself on Capacity

  • What is the name of the smallest unit of data that a computer can store?

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