This document discusses atomic and modular design approaches. It begins by defining modules and patterns, explaining that modules can be independently created and combined in different systems. It then discusses atomic design methodology, which involves designing user interfaces in a hierarchical manner across five stages from atoms to pages. The document also covers creating pattern libraries to promote reusability. It suggests starting by identifying reusable components and not thinking in terms of pages but systems. Overall, the document promotes modular and atomic design principles for building flexible and scalable interfaces.