A byte is a measurement of data that contains eight bits, which is the smallest increment of data on a computer. It’s the smallest addressable unit of memory in most computer architectures, and network protocol documents such as the Internet Protocol refers to an 8-bit byte as an octet. A single byte can be used to represent 2 to the 8th or 256 different values.

The byte was originally created to store a single character, since 256 values is adequate enough to represent all lowercase and uppercase letters, numbers, and symbols in western languages. For example, bytes can represent the letter N, a comma, a percentage sign, or any number from 0 to 256. While the byte was designed to store character data, it has become the fundamental unit of measurement for data storage. But because a byte contains so little storage, the processing and storage capacities of computer hardware are typically in gigabytes (GB) and terabytes (TB).

Byte prefixes

The prefix preceding byte helps identify the size of a byte and how much data is contained within it. Commonly used prefixes include:

  • Kilobyte (KB): A small email without images is approximately 2 KB.
  • Megabyte (MB): A song is approximately 3-4 MB.
  • Gigabyte (GB): A standard DVD may hold up to 4.7 GB of data.
  • Terabyte (TB): 500 hours worth of movies or 310,000 pictures is a TB.
  • Petabyte (PB): 500 billion pages of standard typed text is approximately 1 PB.

For a visual representation of byte size and exact numbers, consider the chart below. It’s worth noting byte sizes are not evenly rounded off (1,024 instead of 1,000 bytes) because computers use binary math instead of a decimal system.


Webopedia Staff
Since 1995, more than 100 tech experts and researchers have kept Webopedia’s definitions, articles, and study guides up to date. For more information on current editorial staff, please visit our About page.

Top Articles

List of Windows Operating System Versions & History [In Order]

The Windows operating system (Windows OS) refers to a family of operating systems developed by Microsoft Corporation. We look at the history of Windows...

How to Create a Website Shortcut on Your Desktop

Website Shortcut on Your Desktop reviewed by Web Webster   This Webopedia guide will show you how to create a website shortcut on your desktop using...

What are the Five Generations of Computers? (1st to 5th)

Reviewed by Web Webster Learn about each of the 5 generations of computers and major technology developments that have led to the computing devices that...

Hotmail [Outlook] Email Accounts

Launched in 1996, Hotmail was one of the first public webmail services that could be accessed from any web browser. At its peak in...

Data Annotation

Data annotation involves processing a set of raw data for text, images, sounds,...


Imperva is a cybersecurity company focused...

Barracuda Networks

Barracuda Networks is a multinational cybersecurity...