The given article aims at bringing up the data of the investigation of a term itself as an entity having the capability of being feasible in a language and implied in the sphere of concepts. By its language nature a term is a lexical unit that has some morphological characteristics as any unit of a language, that is, it has its morphological structure that is recognizable in the given language. If it is a borrowing from another language, then the term has the morphological formation typical for the source language. As a unit of a language, a term is characterized by a certain paradigm that allows a term to enter the syntactical structure of a sentence. Nevertheless, the sphere of the use of the term is limited, for example, it cannot be used for stylistical colouring of a sentence, and a term denotes only a concept from a definite closed terminological area. As a rule, a term has a strict definition of the concept, and it exists as a marker of this concept in the specialized terminological sphere. The correlation between the marker of the concept (a term) and the concept itself is strictly rigid. In case the concept is modified, the marker of this concept will be changed. The topic of the discussion on the nature of a term has a long history in linguistics, nevertheless, it is still challenging and many linguists are so far tackling the obscure issues of the nature of a term and its definition. In this article we have brought some approaches and findings in the sphere of terminology as an area of general linguistics. The tread of narration was provided by our personal perception of a term as a marker of a certain concept and it was based on the data of our investigation of the corpora of terms from the texts extracted from various branches of science and technology.