Topology is a classical branch of mathematics, born essentially from Euler’s studies in the XVII century, which deals with abstract notion shape and geometry. Last decades were characterized by renewed interest topology topology-based tools, due to birth computational topological data analysis (TDA). A large novel family methods algorithms computing features descriptors (e.g., persistent homolo...

Abstract In this chapter we briefly introduce important concepts from homology theory and highlight how some results Chap. 3 can be understood through the lens of algebraic topology. This accumulates in showing that Euler characteristic by means CW complexes, or intersection theory.

Abstract This chapter presents the main general topological tools, as used in later parts. In particular we highlight manifolds, homotopies and retractions.