What is this? And why am I doing this?

As is usual for a student at graduate level, I read a bunch of academic articles, books, etc. I have decided to write expositions/summaries for some of them where the level of detail would vary. The motivation behind this is three-fold. Firstly, writing it down, and having to explain something greatly enhances my level of understanding. Moreover, for the material that I do not directly use, the details get lost on me after a while. Thus, it is a way to expand the breadth as well as depth. Additionally, I want to improve my (technical) writing skills, and what better way than just do it?