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

1) In information technology, a product is something (for example, a software application) that is created and then made available to customers, usually with a distinct name or order number.

2) In mathematics, a product is the result of arithmetically multiplying numbers or quantities. There can be as few as two terms, or as many as a hundred, a thousand, or a million. Some products contain infinitely many terms.

For products with relatively few terms, the numbers, or multiplicands, can be written one after another, separated by multiplication signs (x). An example is 1/1 x 1/2 x 1/3. This becomes awkward when the number of terms is large. When a product has infinitely many terms, the terms must occur in a definable sequence. This sequence is not always clear when the terms are simply listed and separated by multiplication symbols. For this reason, the product symbol was devised: a large, uppercase Greek letter pi.

To denote 1/1 x 1/2 x 1/3, the following symbology can be used:

The expression on the left-hand side of the equation is the product from n = 1 to n = 3 for 1/ n . The value of n is always an integer. It usually starts at 1 and always increases by 1 for each succeeding term in the product.

Suppose the above sequence of multiplicands is extended without limit according to the obvious pattern. Then the product from n = 1 to unlimited values of n for 1/ n , that is, 1/1 x 1/2 x 1/3 x 1/4 x ..., is denoted like this:

The sideways 8 (called a lemniscate ) means that n continues to increase without limit. It is imprecise to say we are dealing with the product from n = 1 to infinity , but this terminology is often used anyway.

Also see Mathematical Symbols .

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

Related Terms


  • photonics

    - Photonics is an area of study that involves the use of radiant energy (such as light), whose fundamental element is the photon. (WhatIs.com)

  • laser

    - A laser is a coherent and focused beam of photons; coherent, in this context, means that it is all one wavelength, unlike ordinary light which showers on us in many wavelengths. The acronym laser s... (WhatIs.com)

  • cyberextortion

    - Cyberextortion is a crime involving an attack or threat of attack against an enterprise, coupled with a demand for money to avert or stop the attack. (SearchSecurity.com)


  • 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



    Contribute to the conversation

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