Units Of Data Storage Ocr

Units of Data Storage

• Computers use binary numbers to represent data

• Data such as characters, images and sound must be stored as binary

• The smallest unit of data a computer can store is 1 binary digit, otherwise expressed as 1 bit

• 1 bit can only hold one value (2¹), this is not big enough to store all kinds of data, so computers have different ‘Units of Data’

What are units of data?

• A unit of data is a term given to describe different amounts of binary digits stored on a digital device

• These are the units you need to know for GCSE:

Converting between units

• It is often a requirement of the exam to be able to convert between different units of data, for example bytes to megabytes (larger) or kilobytes to bytes (smaller)

• This process involves division, moving up in size of unit and multiplication, moving down in size of unit

• When dealing with all units bigger than a byte we use multiples of 1000

• For example, 2000 kilobytes in megabytes would be 2000 / 1000 = 2 MB and 2 terabytes in gigabytes would be 2 * 1000 = 2000 GB

• When dealing with bits and bytes the same process is used with the value 8 as there are 8 bits in a byte

• For example, 24 bits in bytes would be 24 / 8 = 3 B and 10 bytes in bits would be 10 * 8 = 80 b