This standard aims to facilitate international communication in the field of information and documentation. It presents a set of terms, in three languages, that deal with relevant concepts in the area of information and documentation, along with their definitions, and identifies the relationships that may exist between different entries. The definitions are established so that they do not present particularities specific to a given language. This part of the UNE 50-113 standard refers to the fundamental concepts of Information and Documentation, including the terms of related disciplines that are not specific to any of the other parts of the standard. It contains the fundamental terms for a general introduction to the theory of Information and Documentation, and also the derivatives that are considered most useful for practical applications.