A knowledge base is an organised collection of information that people can find, understand and use.
It may contain definitions, models, policies, guidance, decisions, lessons and other knowledge the organisation needs to preserve and share. Its value depends on clear ownership, reliable content, shared language and regular maintenance—not simply the quantity of material stored.
A knowledge base captures mainly explicit knowledge: what has been recorded and made accessible. It becomes part of a Knowledge Operating System when people also use it, question it and update it as experience and circumstances change.