Can you explain the concept of functional testing and its purpose?

Functional testing is a type of software testing that verifies whether the application's functionalities meet the requirements and specifications. The main goal is to ensure that all functions work correctly from the user's perspective.

For example, if you have a registration form, functional testing will check that entering valid data successfully registers the user, and in case of errors, appropriate error messages appear.

This testing typically does not consider the internal code structure but focuses on inputs and expected outputs.