Since about 4000 years ago, lexicography has been a component of all cultures in which script was known. The path of its development goes from word lists on clay tablets to computer stored data banks. In our day, lexicography has a scientific and a non-scientific form. The former form comprises works on various sources of information and reference that pursue various important purposes, such as: help in the acquisition of the mother tongue and of foreign languages; in various types of acquisition of scientific and technical knowledge; in translation; and in cultural exchange and in ideological developments, either within one`s own or in a foreign linguistic community. The social importance of lexicography is occasionally taken cognizance of even in international politics. The last two decades have witnessed an upsurge in interest in lexicography. On the one hand, international contacts are becoming more intimate in terms both of culture and economy; on the other hand and as far as scientific considerations go, the lexicon is being studied more within the framework of various theories, problems of the vocabulary are being studied within the area of foreign language teaching, and the application of the computer in lexicography and in other fields has brought new problems, together with many advantages. The increase in interest in the lexicon has been accompanied by the emergence of the study of dictionaries as a scientific discipline. This discipline studies the tools of reference as to their forms, structures, the way they are used, their history, and their criticism; ultimately, it is the study of those reference tools in relation to the culture in which they are embedded. The Encyclopedia deals with lexicography and with the study of dictionaries; its three volumes cover the whole area in a great wealth of detail but in a coherent way: authors have written 349 articles in English, French, and German. They are distributed in 38 chapters. The Encyclopedia pursues the following goals: to describe the lexicography of all the language families, with particular attention given to the European languages and their transplanted varieties, to develop a typology of the lexicographic reference books, above all the linguistic dictionaries, within the various cultures and societies, to provide the basis for the study of the lexicon within a general theory of lexicography in relation to the study of various functions of dictionaries in individual cultures and in relation to the theories of the lexicon in various linguistic schools of thought, to develop the methodology of lexicographic work in all its phases, beginning with the appointments of a lexicographic office and ending with the application of the computer, to pinpoint areas in greatest need of improvement both in the lexicographic practice of individual territories and in the theory of lexicography, to offer a rich bibliography both of dictionaries and of secondary literature, to foster the development of lexicography into a discipline that while pursuing practical goals will be suitable for being taught and learned in a scientific way.