Test environments are built to test solutions in a controlled environment without impacting production. They should mimic the production environment. Poorly managed test environments can increase defects in production. Key types of test environments include development, sandbox, QA, pre-production, and production. Effective test environment management includes business and testing team involvement in requirements, integrated test landscapes, loading appropriate test data, access controls, and technical support during testing. Having a dedicated test environment management process can reduce production issues and ensure successful projects.