测试环境层次

For smaller companies (it's not clear how big yours is), three environments (dev, stage, production) are common. Larger companies will often have a QA environment between dev and stage.

These normally break down as follows:

dev: Working code copy. Changes made by developers are deployed here so integration and features can be tested. This environment is rapidly updated and contains the most recent version of the application.

qa: (Not all companies will have this). Environment for quality assurance; this provides a less frequently changed version of the application which testers can perform checks against. This allows reporting on a common revision so developers know whether particular issues found by testers has already been corrected in the development code.

staging: This is the release candidate, and this environment is normally a mirror of the production environment. The staging area contains the "next" version of the application and is used for final stress testing and client/manager approvals before going live.

production: This is the currently released version of the application, accessible to the client/end users. This version preferably does not change except for during scheduled releases.

A stage environment should mirror the production environment as closely as possible.

It is used for verification of deployment procedures - making sure that when code is production ready it can be deployed without causing problems.

That is, code goes to staging - this is comprehensively tested and regressed to ensure that deployment went as planned (and to iron out any issues if it didn't).

The stage environment is a preprod environment that mirrors production. Often, it may have some production data so that a test group composed of actual users and QA testers can confirm that the pre-released code base/data will deploy and work properly in a prod-like environment, usually through scripted use cases and regression tests.

参考：

http://programmers.stackexchange.com/questions/117945/dev-vs-stage-environment-vs-prod-environment

http://msdn.microsoft.com/en-us/library/ms942990(v=cs.70).aspx