1.1 Introduction to Algebraic Topology. Homotopy.

The Chapter 1 of this course will introduce Homotopy and a particular kind of topological spaces: the CW complexes. We define when two maps are homotopic and we use that to give the notion of Homotopy Type of topological spaces. Homotopy is the mathematical translation of the intuitive idea of being able to pass from one map to another, or one topological space to another, "in a continuous fashion".