The topic ``Recurrence relations'' and its place in teaching students of Informatics is discussed in this paper. We represent many arguments about the importance, the necessity and the benefit of studying this subject by Informatics students. They are based on investigation of some fundamental books and textbooks on Discrete Mathematics, Algorithms and Data Structures, Combinatorics, etc. Some methodological aspects of training to solve problems with applying recurrence relations are also given. We hope that the considered topics concern also the school teachers in Mathematics and Informatics and the paper will be useful to them.