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Units of information
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<p>A unit of information is any <a href="/facts/Unit_of_measure/pvTpWbmC">unit of measure</a> of <a href="/facts/Digital_data/JChckAvr">digital data</a> size. In digital <a href="/facts/Computing/Kghtm9fX">computing</a>, a unit of information is used to describe the capacity of a digital <a href="/facts/Digital_data_storage/9MUHANxR">data storage</a> device. In <a href="/facts/Telecommunication/vxoj1cxR">telecommunications</a>, a unit of information is used to describe the throughput of a <a href="/facts/Communication_channel/MtlxEShV">communication channel</a>. In <a href="/facts/Information_theory/qNLH3U5P">information theory</a>, a unit of information is used to measure <a href="/facts/Information/3LdrzXtJ">information</a> contained in messages and the <a href="/facts/Entropy_(information_theory)/NLg4NLvt">entropy</a> of random variables. </p><p>Due to the need to work with data sizes that range from very small to very large, units of information cover a wide range of data sizes. Units are defined as multiples of a smaller unit except for the smallest unit which is based on convention and hardware design. Multiplier prefixes are used to describe relatively large sizes. </p><p>For <a href="/facts/Binary_number/a6JDSRPs">binary</a> <a href="/facts/Computer_hardware/8jSjsCNv">hardware</a>, by far the most common hardware today, the smallest unit is the <a href="/facts/Bit/S972NSaD">bit</a>, a portmanteau of binary digit, which represents a value that is one of two possible values; typically shown as 0 and 1. The <a href="/facts/Nibble/PUaqCEVw">nibble</a>, 4 bits, represents the value of a single <a href="/facts/Hexadecimal/02ohQW22">hexadecimal</a> digit. The <a href="/facts/Byte/BNHUp9Qq">byte</a>, 8 bits, 2 nibbles, is possibly the most commonly known and used base unit to describe data size. The <a href="/facts/Word_(computer_architecture)/2e5umRaj">word</a> is a size that varies by and has a special importance for a particular hardware context. On modern hardware, a word is typically 2, 4 or 8 bytes, but the size varies dramatically on older hardware. Larger sizes can be expressed as multiples of a base unit via <a href="/facts/SI/NShmfzlD">SI</a> <a href="/facts/Metric_prefixes/Y2MzkaeL">metric prefixes</a> (powers of ten) or the newer and generally more accurate <a href="/facts/IEC/zRXRn5Lu">IEC</a> <a href="/facts/Binary_prefixes/oM3wgJgW">binary prefixes</a> (powers of two). </p>