Software Functional testing types

 Functional testing is a type of software testing that focuses on verifying the functional requirements and specifications of a software application. It ensures that the system behaves as expected and meets the intended functionality. Here are some common types of functional testing:

1. Unit Testing: Unit testing focuses on evaluating individual components or units of the software, such as functions, methods, or classes, in isolation. It verifies the correctness of each unit's behavior and ensures that they function as intended.

2. Integration Testing: Integration testing checks the interaction and communication between different modules or components of the software. It validates the integration points, data flow, and interfaces to ensure that the system functions correctly as a whole.

3. System Testing: System testing assesses the fully integrated software system to ensure it meets the specified requirements. It verifies the system's behavior, functionality, and performance in various usage scenarios to ensure that it meets user expectations.

4. User Acceptance Testing (UAT): User Acceptance Testing is carried out by end-users or stakeholders to confirm that the software meets their requirements and business objectives. It focuses on ensuring that the system is usable, reliable, and aligns with the users' expectations.

5. Regression Testing: Regression testing is conducted after making changes or modifications to the software to ensure that the existing functionalities are not adversely affected. It retests previously tested features to ensure that they still work correctly and detects any regressions or unintended side effects.

6. Functional Testing by Business Domain: This type of functional testing focuses on testing specific functionalities or features that are critical or unique to a particular business domain. It guarantees that the software complies with the specific requirements and regulations of the industry.

7. Smoke Testing: Smoke testing, or build verification testing, is conducted to check the essential and critical functionalities of the software. It ensures that the most crucial features are working correctly before conducting further comprehensive testing.

8. Sanity Testing: Sanity testing is a subset of regression testing that quickly checks if the recent changes or fixes in the software have not introduced any major issues or defects. It emphasizes verifying that the essential functionalities continue to work as intended.

9. Exploratory Testing: Exploratory testing involves simultaneous test design and execution to uncover defects, usability issues, and unexpected behaviors. It relies on the tester's knowledge, creativity, and intuition to explore the software and find potential defects.

10. Boundary Testing: Boundary testing focuses on testing the boundaries or limits of input parameters. It verifies how the system behaves at the lower and upper limits of input ranges, ensuring that it handles boundary values correctly and does not produce unexpected results or errors.

11. Equivalence Partitioning: Equivalence partitioning divides the input data into different classes or partitions and selects representative test cases from each partition. It ensures that the software is tested with a diverse range of inputs without redundant test cases.

These are some common types of functional testing, and the specific types may vary depending on the project, software application, and requirements. It's important to select the appropriate functional testing techniques based on the system's functionalities and the desired level of test coverage.