## Abstract

The central notion in topology is the concept of “continuity of functions” between topological spaces. A discussion of this concept and some other notions related to mappings is the object of the first section. In the second section, we consider the problem of topologizing the Cartesian products of a family of topological spaces in some natural and useful way. Here, we are mainly concerned with the “Tychonoff topology,” which is the smallest topology for a product of topological spaces such that each projection is continuous.

## Copyright information

© Springer Nature Singapore Pte Ltd. 2019