Environments

Here are the definitions from ITIL v3 Glossary:

Environment

(Service Transition) A subset of the IT Infrastructure that is used for a particular purpose. For Example: Live Environment, Test Environment, Build Environment. It is possible for multiple Environments to share a Configuration Item, for example Test and Live Environments may use different partitions on a single mainframe computer. Also used in the term Physical Environment to mean the accommodation, air conditioning, power system etc.

Environment is also used as a generic term to mean the external conditions that influence or affect something.

Build Environment

(Service Transition) A controlled Environment where Applications, IT Services and other Builds are assembled prior to being moved into a Test or Live Environment.

Development Environment

(Service Design) An Environment used to create or modify IT Services or Applications. Development Environments are not typically subjected to the same degree of control as Test Environments or Live Environments.

Test Environment

(Service Transition) A controlled Environment used to Test Configuration Items, Builds, IT Services, Processes, etc.

Live Environment

(Service Transition) A controlled Environment containing Live Configuration Items used to deliver IT Services to Customers.