Functional Testing-Any requirements related to application functions are called functional requirements. Like login, adding friends, uploading pics, change password, logging out.

In functional testing we test whether the system meets all these requirements.

White Box testing (Structural Testing)-Here we test the internal structure and the code of the website. We test the design implementation of the website. Has the developer used proper design implementation while developing the website. Have they followed the coding standards? Most of the times this is done by developers and not by testers. It is used to ensure that each line of code under test is exercised.

Black Box testing-Testing is like a black box i.e testing the application from front end to check whether the application is working without worrying much about the internal structure of the application.