Knowledge is the collection of facts, inference rules etc. which can be used for a particular purpose. Knowledge requires the use of data and information. It combines relationships, correlations, dependencies with data and information.
The basic components of knowledge are:
1) A set of collected data
2) A form of belief or hypothesis
3) A kind of information.
Knowledge is different from data. Data is the collection of raw materials where as knowledge is the collection of some well specified inference rules and facts. Knowledge is also different from belief and hypothesis. Belief is any meaningful and coherent expression that can be represented. Belief may be true or false. A hypothesis is a justified belief that is not known to be true. A hypothesis is a belief which is backed up with some supporting evidence but it may still be false. So knowledge can be defined as true justified knowledge.
KNOWLEDGE BASED SYSTEMS
Knowledge based systems get their power from the expert knowledge that has been coded into facts, rules, heuristics and procedures. The knowledge is stored in a knowledge base separate from the control and inferencing components. Knowledge is important and essential for knowledge based intelligent behaviour.
Figure A typical Knowledge based system
Any choice of representation will depend on the type of problem to be solved and the inference methods available. Knowledge may be vague, contradictory or incomplete. Thus, knowledge is information about objects, concepts and relationships that are assumed to exist in a particular area of interest.