Abstract:Information and knowledge organization by keywords is presently eff ected in information and retrieval systems -not only in various taxonomic structures, but also in new structures of a folksonomic and ontological nature as well as mind maps. The need for a fresh look at keyword results from the new possibilities of document and information indexing, especially of social (collaborative) indexing, among others. This will require new research and scholarly refl ection on information processing by both computer systems and the human mind. And this will, in turn, create the need to look at both information and knowledge organization and keywords in terms of the network organization of information and knowledge. This topic is current, owing to the application of keywords in the WWW system, subject indexes, OPACs, full-text systems, and digital libraries. The considerations are concluded by an att empt to answer the question contained in the title relating to the roles of keywords in information and knowledge organization for current information systems. This study has shown that, by using keywords, we essentially deal with a natural language in a meta-information function, not only with an artifi cial keyword language; "-nomic" systems based on hierarchy are usually strongly structured, while the systems that use keywords are hardly structured. Information and knowledge organization by keywords is frequently based on the indexing practice, which means that it is carried out bott om up (with classifi cation being a reverse process).