The modern world information flow has no borders, no time, no space, and the process of translation covers almost all spheres of human activity. The translation of specialized texts in the field of information technologies, economy, technology has become increasingly important both in terms of volume and social significance. The importance of translation is constantly growing. The trend towards globalization, which is observed in the 20th-21st centuries, has been prepared by the translators’ committed work. The main feature of this period of time is the integration processes in culture, science, economics, which inevitably lead to an increase in the number of multilingual contacts. The work of translators promotes the openness of society and serves as an integral link between people living in different parts of the world. The peculiar nature of translation is intended to replace the source text so that it is considered completely identical to the original one. However, it is clear that the absolute identity of the translation to the original text is unattainable and that this shouldn’t interfere with inter-language communication. Due to the lack of absolute identity, the relation between the content of the source text and the target text is defined by the term "equivalence," denoting the commonality of the content, that is the semantic proximity. Since the importance of maximum overlap between these texts seems obvious, equivalence is usually considered as the main feature and condition of the existence of translation. This article is dedicated to the study of synonymy as a type of semantic relationship of language units, resulting in full or partial coincidence of their meanings. Synonymy reflects the properties of the objective world in the language and is determined by various degrees of semantic proximity of the language units. There are several approaches to the study of synonymy: focus on identity or similarity of meanings, logical equivalence and its complete or partial reciprocity in the text, its evaluative and stylistic features. There is a narrow and wide understanding of the concept of synonym, depending on the properties of language units to fully or partially coincide in their meaning. The first is of great value in terms of paraphrasing, the second specifying the content of the designated object and revealing its various aspects. Lexical synonymy is considered to be the most representative and functionally diverse in the language. The semantic essence of synonymy is the equivalence of the entire volume of values of lexical units, their separate features or identical ones. This serves the basis for distinguishing between complete (absolute) and partial (relative) synonymy. The phenomenon of synonymy is a universal phenomenon that combines language facts in time, in local and social versions.