Test Environment
// Definition
The infrastructure where tests run — hardware, OS, database, network, and configuration. Differences between test and production are a leading source of bugs that pass tests but fail in production.
// Related terms
Test Fixture
A known, fixed state used as a baseline for tests — sample data, a seeded database, or a configured environment that ensures repeatability across runs.
Test Data Management
Provisioning, masking, refreshing, and tearing down data needed by tests. Done well, it's invisible. Done badly, it's the reason a third of tests fail on Mondays.
Containerisation
Packaging an application together with its dependencies into a portable image (typically Docker) that runs identically on a developer laptop, CI, and production. Eliminates 'works on my machine' and underpins modern test environments.