Neural Networks
Obsidian is sometimes called a second brain. This is because the structure of a vault, with notes connected by links, is the way a neural network is structured, with notes as nodes and links as edges. Such data structures are typically represented by graphs, and Obsidian has a built-in Graph View for this purpose.
In this video, I visually explore the concept of Obsidian as a second brain. The original can be found here.