Below are some of the important testing types which are supported by Selenium:-
1. Functional testing:-
Functional testing verifies that each function of the software application operates in conformance with the required specification.
2.Regression Testing:-
Regression Testing is defined as a type of software testing to confirm that a recent program or code change has not adversely affected existing features.
I am mentioning the Selenium Training Course which you should take up to learn it properly with a valuable certificate. You can also read the following Selenium Tutorial to learn it sharper. Here is the video tutorial that I followed while I was learning Selenium..