This book, one of the few in the national and world scientific literature, provides information about mathematical concepts, terms and designations. The reader will know who and when introduced the concept, definition and term; how it was called at its first appearance; when the modern term arose and by whom it was proposed; what it means in the exact translation of the Russian language; who owns the designation (if any) Information is given in alphabetical order . The handbook will be useful to a wide range of readers - mathematicians and historians of science. A lot of interesting things will be found in it by researchers, teachers, graduate students, students, high school students and just lovers of mathematics .