The traditional, Carnap's definition of semantics declares semantics to be the study of the relations between expressions and extralinguistic entities (while syntax is the the study of the relations among expressions and pragmatics is the study of the relations between expressions and their users). The paper argues that this definition is useless and proposes another one: semantics is the study of the 'basic' rules for using expressions (while syntax is the study of which expressions are used and pragmatics is the study of the residual aspects of their use).