The article is devoted to researching computer lexicography and aims at regarding basic concepts of the applied scientific discipline in linguistics.Such tasks of computer lexicography, as parsing, creating a lexical database, lexical analysis of electronic dictionaries, estimation of the number of multi-valued-single-valued words, automatic extraction of hyponym-hypernym relationships, displaying values when extracting from several dictionaries at once, defining a value within a single dictionary and extracting information using a set of monolingual and translation dictionaries are discussed.The major principles of a computer dictionary compiling and an example of a dictionary entry are provided.Such terms as lexeme, lemma and lemmatization are explained.Corpus lexicography as a relatively new branch of computer lexicography is overviewed.The authors also note that computational linguistics is closely related to the central problem of artificial intelligence.It is emphasized that although the aims of traditional and computer lexicography are mainly the same, their methods, tools and approaches differ significantly.It is shown that such features of electronic dictionaries as multifunctionality, the use of multimedia, possibility of updating, convenient search and many others provide considerable advantages over conventional paper dictionaries.Practical lexicography is defined as the process of compiling dictionaries of various types on the basis of theoretical developments.The process of creating electronic dictionaries is discussed.Depending on the purpose of the dictionary, its volume, the order of the words in it, the object of description and other criteria, dictionaries can be divided into various types.Such dictionary types as explanatory, translation, etymological, frequency etc. are described.It is concluded that for researchers working in the sphere of computer lexicography and other fields of applied linguistics, understanding of the basic principles, tasks and functionality of computer-based dictionaries is vital.