Information resources are of two kinds, namely, Documentary and Non-Documentary Sources.
A document embodies thought. It is a record of work on paper or other material for easy physical handling, transportation across space, and preservation through time. It may be said that the thought content of a document represents the information it contains. A document may be a macro-document like a book, monograph, thesis, dissertation, report, etc., or a micro-document like an article in a periodical. Documents have also been grouped as Conventional, Non-Conventional, Neo-Conventional, Meta documents,etc. As a matter of fact, these documents are available in various physical forms such as books, periodicals and also as audio-visuals. Details of each type are given in the succeeding sections and sub-sections.
On the other hand, non-documentary sources include:
• Institutional Sources
• Human Sources
• Information Gatekeepers
• Guides, Advisors, Consultants
• Vendors, Contractors, Collaborators, etc.