Which framework is primarily concerned with testing each component in isolation?

The Unit Test Framework is specifically designed to focus on testing individual components or modules in isolation. This framework allows developers to write tests that evaluate the functionality of a single unit of code without considering external systems or dependencies. This isolation enables developers to pinpoint issues within that unit, ensuring that each component performs as expected before it is integrated with other parts of the system.

By using the Unit Test Framework, developers can efficiently verify the correctness of their code at an early stage, which helps facilitate a more robust overall system. Additionally, because tests are executed frequently during development, any defects can be identified and addressed immediately, contributing to a better quality of software in the long run.

In contrast, other frameworks like the Integration Testing Framework focus on testing the interaction between multiple components, the System Testing Framework assesses the complete and integrated system as a whole, and the End-to-End Testing Framework tests the entire application flow from start to finish, all of which do not concentrate on individual units.