Indexes, particularly subject indexes, are very often a part of any form of publication: "traditional" printed documents, e-documents and web-documents, and yet the principles of construction and types of indexes are the same for all of them. Indexing is the procedure of constructing an index – definition and choice of access points to the documents/collection of documents/knowledge. Index and indexing is a way of organising knowledge, a tool designed to serve as a helpful communication between the information and the one who needs it.