💻IT: Latency (Definitions)

"The fixed cost of servicing a request, such as sending a message or accessing information from a disk. In parallel computing, the term most often is used to refer to the time it takes to send an empty message over the communication medium, from the time the send routine is called to the time the empty message is received by the recipient. Programs that generate large numbers of small messages are sensitive to the latency and are called latency-bound programs." (Beverly A Sanders, "Patterns for Parallel Programming", 2004)

"The amount of time it takes a system to deliver data in response to a request. For mass storage devices, it is the time it takes to place the read or write heads over the desired spot on the media. In networks, it is a function of the electrical and software properties of the network connection." (Tom Petrocelli, "Data Protection and Information Lifecycle Management", 2005)

"The time delay it takes for a network packet to travel from one destination to another." (John Goodson & Robert A Steward, "The Data Access Handbook", 2009)

"The time it takes for a system to respond to an input." (W Roy Schulte & K Chandy, "Event Processing: Designing IT Systems for Agile Companies", 2009)

"A period of time that the computer must wait while a disk drive is positioning itself to read a particular block of data." (Rod Stephens, "Start Here!™ Fundamentals of Microsoft® .NET Programming", 2011)

"The measure of time between two events, such as the initiation and completion of an event, or the read on one system and the write to another system." (DAMA International, "The DAMA Dictionary of Data Management", 2011)

"The time period from start to completion of a unit of work." (Max Domeika, "Software Development for Embedded Multi-core Systems", 2011)

"The time it takes to complete a task - that is, the time between when the task begins and when it ends. Latency has units of time. The scale can be anywhere from nanoseconds to days. Lower latency is better in general." (Michael McCool et al, "Structured Parallel Programming", 2012)

"The amount of time lag before a service executes in an environment. Some applications require less latency and need to respond in near real time, whereas other applications are less time-sensitive." (Marcia Kaufman et al, "Big Data For Dummies", 2013)

"A delay. Can apply to the sending, processing, transmission, storage, or receiving of information." (Mike Harwood, "Internet Security: How to Defend Against Attackers on the Web" 2nd Ed., 2015)

"A period of waiting for another component to deliver data needed to proceed." (Faithe Wempen, "Computing Fundamentals: Introduction to Computers", 2015)

"The time it takes for the specified sector to be in position under the read/write head" (Nell Dale & John Lewis, "Computer Science Illuminated" 6th Ed., 2015)

"The delay between when an action such as transmitting data is taken and when it has an effect." (O Sami Saydjari, "Engineering Trustworthy Systems: Get Cybersecurity Design Right the First Time", 2018)