Lexicography, the science of dictionary-compiling, is closely connected with lexicology, both dealing with the same problems – the form, meaning, usage, and origin of vocabulary units and making use of each other’s achievements. The word “lexicography” derives from the Greek “λεξικογράφος» (lexikographos), from “λεξικόν» (lexicon), neut. of “λεξικός» (lexikos), “of or for words, from “λέξις» (lexis), “speech”, “word”, and “γράφω» (grapho) in the meaning – to scratch, to inscribe, to write. Lexicography has a common object of study with Lexicology both describe the vocabulary of a language. The essential difference between the two lies in the degree of systematization and completeness each of them is able to achieve. Lexicology aims at systematization revealing characteristic features of words it means that lexicology concentrates more on general properties and features that can be viewed as systematic analysis. The province of lexicography is the semantic, formal, and functional description of all individual words and phrases. Lexicographers have to arrange it most often according to a purely external characteristic, namely alphabetically. It goes without saying that neither of these branches of linguistics could develop successfully without the other, their relationship being essentially that of theory and practice dealing with the same objects of reality. Lexicography is divided into two related disciplines:Practical lexicography is the art of compiling, writing and editing dictionaries. Practical lexicographic work involves several activities, and the compilation of dictionaries requires careful consideration some of the following aspects: 

 defi ning the communicative and cognitive functions of the dictionary 

 selecting and organizing the components of the dictionary 

 choosing the appropriate structures for presenting the data in the dictionary (i.e. frame structure, distribution structure, macro-structure, micro-structure) 

 selecting words and affi xes for systematization as entries selecting collocations, phrases and examples 

 choosing lemma forms for each word or part of word to be lemmatized аннотация формируется для каждого слова organizing defi nitions and specifying pronunciations of words 

 selecting equivalents in bi- and multi-lingual dictionaries 

 translating words, collocations, phrases and examples in bi- and multilingual dictionaries 

 designing the best way in which users can access the data in printed and electronic dictionaries scientifi c disciplineTheoretical lexicography (or Metalexicography) is the scientific discipline of analyzing and describing the semantic, syntagmatic and paradigmatic relationships within the lexicon (vocabulary) of a language, developing theories of dictionary components and structures linking the data in dictionaries. Metalexicography can be subdivided into three groups of research: 1. User research. 2. Dictionary criticism. 3. Systematic dictionary research.User research formulates theories and methods for examining dictionary use and makes observations concerning general models of improving the use dictionaries, regards the needs of users in specifi c types of situation and how users may best access the data incorporated in printed and electronic dictionaries.Dictionary criticism is concerned with dictionary reviews as well as with general models for assessment for existing dictionaries.Systematic dictionaries research is the formulation of novel [na:vl (Am)] – new or improved theories, with aims to develop new principles and the design that can improve the quality of future dictionaries. Lexicography can be grouped into: 

General lexicography focuses on the design, compilation, use and evaluation of general dictionaries, i.e. dictionaries that provide a description of the language in general use. Such a dictionary is usually called a general dictionary or LGP dictionary. Specialized lexicography focuses on the design, compilation, use and evaluation of specialized dictionaries, i.e. dictionaries that are devoted to a (relatively restricted) set of linguistic and factual elements of one or more specialist subject fi elds. Such a dictionary is usually called a specialized dictionary or LSP dictionary. English lexicography is probably the richest in the world with respect to variety and scope of the published dictionaries. The demand for English dictionaries is very great all over the world. Nowadays it is impossible to imagine our life without dictionaries. With the help of the dictionaries the learner not only enriches his own vocabulary, he studies together with it the culture, traditions and mentality of the country.