Use case testing is a functional testing technique that attempts to validate the functionality of the system by evaluating particular use cases. A use case entails a particular context in which a user interacts with the system for a particular purpose. This testing type confirms that the system operates appropriately in relation to actual situations or contexts.

Significant components of use case testing include:

Focus on the User: It pays attention on how users operate the system instead of verifying each component in isolation.

Complete Transactions: It includes entire transactions from initiation to completion, success scenarios to failure scenarios.

Finding Gaps: It aids in finding gaps that other testing approaches might not find such as lack of certain functionality and anomalous results.

In the context of a login system, a use case would include a user inputting their login ID and password. The test will validate the success scenario (successful unimpeded user access after employee authentication) as well as the failure scenarios (incorrect entry of password, restricted attempts over a set number with unassistable guidance, etc.).