A personal knowledge database is a place where you not only write things down, but where everything you write may eventually become structured, linked and queryable data.

In SilverBullet your notes are kept as a Space (folder) of Markdown Page|Pages on disk. As you write, SilverBullet continuously indexes your content — Page|pages, Link|links, Task|tasks, list items and their Attribute|attributes — into queryable Object|Objects. You can then slice and reshape that data with Space Lua/Integrated Query|Queries (SLIQ) and surface the results right inside your notes.

It is SilverBullet’s take on personal knowledge management (PKM). From Wikipedia:

Personal knowledge management (PKM) is a process of collecting information that a person uses to gather, classify, store, search, retrieve and share knowledge in their daily activities and the way in which these processes support work activities. It is a response to the idea that knowledge workers need to be responsible for their own growth and learning. It is a bottom-up approach to knowledge management.