Staging site, in website design, is a website

Website

A website, also written as Web site, web site, or simply site, is a collection of related web pages containing images, videos or other digital assets. A website is hosted on at least one web server, accessible via a network such as the Internet or a private local area network through an Internet...

 used to assemble, test and review its newer versions before it is moved into production. This phase follows the development phase

Development environment

In hosted software development, a development environment refers to a server tier designated to a specific stage in a release process....

. The staging phase of the software life-cycle is often tested on hardware that mirrors hardware used in the production environment. The staging site is often different from the development site, and provides a QA

Quality Assurance

Quality assurance, or QA for short, is the systematic monitoring and evaluation of the various aspects of a project, service or facility to maximize the probability that minimum standards of quality are being attained by the production process...

zone that is separate from the development or production environments.

Normally before deploying an updated version of software to the production environment, the update has been tested in the staging environment. The staging server will resemble the production environment where the clients can do the user acceptance testing activities. Tests on Staging server/site should be passed before deployment of system on live server, i.e. production environment.