The article is based on the study that involved 115 students acquiring professional pedagogical education and 115 practicing teachers. The article describes the process of emergence of individual conceptual and terminological frameworks during various stages of professional communication, i.e. training and pedagogical activity. Individual frameworks of concepts have been studied through comparison of interpretations of definitions of basic didactic concepts by respondents (a total of 3487 definitions have been processed), 353 concept maps, as well as wordings of professionally significant problems in which didactic terms were used as well (a total of 400 statements have been analyzed). Factors that influence the nature of how teachers use didactic terms in various instances of professional communication have been described.