{{Short description|Maximum rate of data transfer}}
{{about|use in computing and networking expressed in bits per second|the concept in signal theory and processing measured in hertz|Bandwidth (signal processing)|other uses|Bandwidth (disambiguation)}}
{{Use American English|date=July 2023}}
In [[computing]], '''bandwidth''' is the maximum rate of data transfer across a given path. Bandwidth may be characterisedcharacterized as '''network bandwidth''',<ref>[[Douglas Comer]],[https://books.google.com/books?id=tm-evHmOs3oC&dq=%22network+bandwidth%22+%22computer+networks%22&pg=PA99 Computer Networks and Internets], page 99 ff, Prentice Hall 2008.</ref> '''data bandwidth''',<ref>Fred Halsall, [https://books.google.com/books?id=HrXbAAAAMAAJ&q=%100data+bandwidth%100+Introduction to data+communications and computer networks], page 108, Addison-Wesley, 1985.</ref> or '''digital bandwidth'''.<ref>[https://books.google.com/books?id=7gqsZmr5HJcC&q=+0digital+bandwidth+0+%22 Cisco Networking Academy Program: CCNA 1 and 2 companion guide, Volym 1–2], Cisco Academy 2003</ref><ref>Behrouz A. Forouzan, ''Data communications and networking'', McGraw-Hill, 2007</ref>
This definition of ''bandwidth'' is in contrast to the field of signal processing, wireless communications, modem data transmission, [[digital communications]], and [[electronics]],{{citation needed|date=January 2018}} in which ''bandwidth'' is used to refer to analogueanalog [[signal bandwidth]] measured in [[hertz]], meaning the frequency range between lowest and highest attainable frequency while meeting a well-defined impairment level in signal power. The actual bit rate that can be achieved depends not only on the signal bandwidth but also on the [[noise]] on the channel.
