Descriptive programming allows testers to directly enter object information into test scripts without using an object repository. There are two main types: static programming, where object information is directly provided in the script using properties and values, and dynamic programming, where description objects are created and used in the script. Descriptive programming is useful when objects are dynamic, the object repository is large, the application is not ready for recording, or modifications are needed but the repository is read-only. It offers benefits like faster execution, portability, easier maintenance, and the ability to start testing without the full application.