Word forms ? civil, civility, civilized, civilization.

Could someone tell me what the right word or definition to describe the following three examples.

For example, eat, ate, eaten eating. These are verb forms.

What are these below? Word forms? Word sequences? I tried to search on the net using these words but couldn't find anything.

I would like to study the different forms of words and how they are used in sentences, but I don't know how to define this area of study.

civil, civility, civilized, civilization.

equal, equality, equalize, equalization.

fertile, fertility, fertilize, fertilization.

Thanks

Lee