The study of DevOps is worthless without having a word of unit testing. It is at the developer’s level. Unit testing is the practice of testing the code at the smallest possible chunks. Typically each method in a class will be tested. Various tools and frameworks are helpful to code.
It also helps in seeing the code that has passed or failed. The aim is to make sure that the code entered is working the way developer wanted. It must meet the needs of the software to work. The unit mentioned might be a module but, commonly it’s a particular function in DevOps.
For example, if a programmer has passed two elements a and b to give a+b. Now if the method in the class works, the code is passed. If not, the code is failed. Well, this is much dependent on the developer’s input and the technology on which he/she is working.