# Megabytes – Gigabytes – Terabyte – Units of Digital Measurement

What is a byte, and what are the other units of measure for digital information?

A `byte` is a unit of measure for digital information. A single byte contains eight consecutive bits, and is capable of storing a single ASCII character, like “h”.

A `kilobyte` (KB) is 1,024 bytes, not one thousand bytes as might be expected. This odd number results from the fact that computers use binary (base two) math, instead of a decimal (base ten) system.

Computer storage and memory is often measured in `megabytes` (MB). A medium-sized novel contains about 1MB of information. 1MB is 1,024 kilobytes, or 1,048,576 (1024x1024) bytes, not one million bytes. Again, this number results from the fact that computers use binary math.

1 `kilobyte` (KB) is 1,024 `bytes`

1 `MB` is 1,024 `kilobytes`

1 `gigabyte` (GB) is 1,024MB, or 1,073,741,824 (1024x1024x1024) `bytes`.

1 `terabyte` (TB) is 1,024GB; 1TB is about the same amount of information as all of the books in a large library, or roughly 1,610 CDs worth of data.

1 `petabyte` (PB) is 1,024TB. Indiana University is now building storage systems capable of holding petabytes of data.

1 `exabyte` (EB) is 1,024PB.

1 `zettabyte` (ZB) is 1,024EB.

1 `yottabyte` (YB) 1,024ZB.