Knowledge:

The dictionary definition of knowledge is 'organised body of information or the comprehension and understanding, consequent on having acquired an organised body of facts' (Random House Dictionary of English Language, 1983). In common usage of the word, we say 'a knowledge of French is desirable for the post' which means that a person having reasonable acquaintance with French is eligible for the position. A book of knowledge is the title of a book which contains data and information about selected topics which would be useful to students appearing for competitive examinations. Similarly, we often refer to a library as a storehouse of knowledge, meaning thereby, that a library stores documents which contain information and knowledge. Therefore, in common parlance, we use information and knowledge more or less synonymously, without making any distinction between them. But, we must understand the usage of these words a little more precisely in our professional studies. 

Data are sets of facts or observations and they are turned into useful information after sorting, compressing and organising them into a meaningful guide to form a basis for further study and research. 

Patterns of such information are then built into a coherent body of knowledge. Knowledge, hence, consists of an organised body of information. This interpretative knowledge forms the 

The following example may make these ideas a little more clear: basis of insights and judgements. 

Data   Cotton 

Information Yarn 

Knowledge Cloth 

Cotton can be loomed into yarns which in turn can be weaved into cloth. So also data can weaved into information which can be used to form an organised body of knowledge. In general, both data and information are the building blocks of knowledge and all three are handled in libraries offering different types of services.