Dynamic Resource Definitions enable Humanitec to manage the full lifecycle of an External Resource. The External Resource can be created when needed and destroyed when no longer needed. A good example of a Dynamic Resource Definition is a database you use in one of your development or QA environments. Whenever a new development or QA environment is added, a new database is created and seeded as needed. The database can be removed when the Environment is deleted (i.e., no longer needed).