This scientific article analyzes the theoretical foundations of the concept of loanwords within the framework of modern linguistics, as well as their formation mechanisms and functional role in the language system in a comprehensive manner. The study scientifically explains the intensification of lexical exchange processes between languages as a result of globalization, cultural integration, and the expansion of communicative interactions. The article develops a classification of loanwords based on their sources of origin, semantic and phonetic adaptation, as well as levels of morphological integration. In addition, the features of the use of borrowed units in languages belonging to different language families are examined through comparative analysis.