The purpose of the book by D. Barron, who is well known to readers from his two books from the series "Mathematical Computer Support," is to help understand the existing variety of programming languages. The general principles of their construction are illustrated by examples from such well-known languages ​ ​ as ALGOL-60, FORTRAN, ALGOL-68, PL1, APL. In an accessible and interesting form, but at the same time quite carefully, the basic concepts of programming languages ​ ​ are considered, considerable attention is paid to input-output and the general structure of programs.