# Storage Sizes

Computers are made up of complicated hardware that stores and processes data. If you break a computer down into its most basic components you have millions of circuits that either allow electricity to flow, or not. Imagine a whole row of light switches that you can switch on and off in different combinations to mean different things. Each switch is either on or off. It only has two states. That is why everything stored in a computer can be stored as a series of 1s and 0s. This is called binary.

A single 1 or 0 is a binary digit, or a bit for short. A group of 8 bits is a byte.

Imagine you have taken a bite of an apple, you might call that a nibble. So four bits, half a byte, is called a nibble.

The list below represents internal memory allocations:

• 4 bits = 1 nibble
• 8 bits = 1 byte
• 1024 bits = 1 kilobyte
• 1024 kilobytes = 1 megabyte
• 1024 megabytes = 1 gigabyte
• 1024 gigabytes = 1 terabyte
• 1024 terabytes = 1 petabyte
• Computers use the binary system to store numbers and perform binary arithmetic and logic operations. Computer systems have got larger and larger and now the capacity of scondary storage systems is commonly measured in terabyts (TB). Vast computers used in universities and industrial applications have storage which is now measured in petabytes. Scientists have estimated that the human brain has a memiry capactiy of 2.5 petabytes so computers have some catching up to do!