TAE materials commonly describe feature toggles (feature flags) as a mechanism to control which features are active in a given release or deployment without necessarily changing the codebase structure for each variant. Because toggles determine what functionality is actually enabled, they provide a practical basis for selecting which automated tests should run for that release configuration. When a feature is disabled via a toggle, executing tests for it can create false failures or wasted effort; when enabled, the corresponding tests become relevant as release evidence. Feature-driven development is a product/development planning approach and does not, by itself, provide an operational mechanism to declare what is active at runtime. Feature files (often associated with BDD) specify behavior scenarios, but they do not inherently indicate whether a feature is active in a particular release unless explicitly tied to toggles or release configuration. TDD focuses on coding practices at the unit level and similarly does not specify release-time feature availability. Feature toggles directly express “active vs. inactive” functionality and can be used to drive risk-based and relevance-based test execution decisions, matching the requirement precisely.