What is function? - Definition from WhatIs.com
Part of the Computing fundamentals glossary:

In information technology, the term function (pronounced FUHNK-shun ) has a number of meanings. It's taken from the Latin "functio" - to perform.

1) In its most general use, a function is what a given entity does in being what it is.

2) In C language and other programming, a function is a named procedure that performs a distinct service. The language statement that requests the function is called a function call . Programming languages usually come with a compiler and a set of "canned" functions that a programmer can specify by writing language statements. These provided functions are sometimes referred to as library routines . Some functions are self-sufficient and can return results to the requesting program without help. Other functions need to make requests of the operating system in order to perform their work.

3) In mathematics, a function is a relationship between two variables called the independent variable and the dependent variable. The dependent variable has at most one value for any specific value of the independent variable. A function is usually symbolized by a lowercase, italicized letter of the alphabet, followed by the independent variable in parentheses. For example, the expression y = f ( x ), read " y equals f of x ," means that a dependent variable y is a function of the independent variable x . Functions are often graphed, and they usually appear as lines or curves on a coordinate plane.

4) In a hardware device, a function is one complete physical movement that has a discernible consequence relative to the device's purposes. In a printer, for example, this might be a carriage return or a line feed.

This was last updated in September 2005
Posted by: Margaret Rouse

Related Terms

Definitions

  • unique identifier (UID)

    - A unique identifier (UID) is a numeric or alphanumeric string that is associated with a single entity within a given system. (WhatIs.com)

  • cache memory

    - Cache memory, also called CPU memory, is random access memory (RAM) that a computer microprocessor can access more quickly than it can access regular RAM. (SearchStorage.com)

  • service-oriented architecture (SOA)

    - Service oriented architecture (SOA) is a technique that involves the interaction between loosely coupled services that function independently. (SearchSOA.com)

Glossaries

  • Computing fundamentals

    - Terms related to computer fundamentals, including computer hardware definitions and words and phrases about software, operating systems, peripherals and troubleshooting.

  • Internet applications

    - This WhatIs.com glossary contains terms related to Internet applications, including definitions about Software as a Service (SaaS) delivery models and words and phrases about web sites, e-commerce ...

Ask a Question. Find an Answer.Powered by ITKnowledgeExchange.com

Ask An IT Question

Get answers from your peers on your most technical challenges

Ask Question

Tech TalkComment

Share
Comments

    Results

    Contribute to the conversation

    All fields are required. Comments will appear at the bottom of the article.