This course is divided in 3 major sections:

Section I:

1. The fundamental concepts and theory related to unit testing in general, regardless of programming language;

Section II:

1. The fundamental techniques and features of JUnit 4 (a pre-requisite for part IIof the course);

Section III:

1. The architecture and extension model introduced in JUnit 5;

2. The advanced techniques and features introduced in JUnit 5.

If you are a totally new to unit testing in general and unit testing in Java in particular then Ihighly recommend that you take the three sections in the order presented above.

If you're familiar with JUnit 4 then you may skip Section II. I'd still recommend that you take Section I though since it introduces fundamental concepts that you may not be familiar with pertaining with unit testing in general even if you've some experience in JUnit 4.