Wikilink.

Definition

A link written between double brackets that connects one note or page to another by its title, with no URL involved. Popularized by wikis and tools like Obsidian, each wikilink is an explicit, human-made edge — and the sum of them forms a knowledge graph that can be navigated in both directions and queried as data. It's the cheapest primitive for turning a folder of documents into a connected knowledge base.