A lot vs. Alot: 9 Grammatical Pitfalls
The subfield of artificial intelligence concerned with designing and using systems for storing knowledge - facts and rules about some subject.
A body of formally represented knowledge is based on a conceptualisation - an abstract view of the world that we wish to represent. In order to manipulate this knowledge we must specify how the abstract conceptualisation is represented as a concrete data structure. An ontology is an explicit specification of a conceptualisation.