At the beginning paragraph of chapter 1 in Hatcher’s Algebraic Topology it says:
Algebraic topology can be roughly defined as the study of techniques for forming algebraic images of topological spaces. Most often these algebraic images are groups, but more elaborate structures such as rings, modules, and algebras also arise. The mechanisms that create these images — the ‘lanterns’ of algebraic topology, one might say — are known formally as functors and have the characteristic feature that they form images not only of spaces but also of maps. Thus, continuous maps between spaces are projected onto homomorphisms between their algebraic images, so topo- logically related spaces have algebraically related images.
With suitably constructed lanterns one might hope to be able to form images with enough detail to reconstruct accurately the shapes of all spaces, or at least of large and interesting classes of spaces.This is one of the main goals of algebraic topology, and to a surprising extent this goal is achieved.
I attempted to search for more information about this method of reconstruction but failed to find anything. Could anyone please give some details of this reconstruction of topological spaces?