Hi: I am new here. I went over the fAQ's, still, sorry if I break protocol.
I am pretty confused about induced maps in different areas of algebraic
topology; I do know how these induced maps are defined in many cases,
but I definitely do not understand well-enough the rules governing when
a map between two topological spaces X,Y , induces a map in homology,
AFAIK, if we have a map f:X-->Y , and this map takes cycles to cycles and boundaries to boundaries, then this map "passes to homology" (not clear what that means.).
Problem(at least to me) is that this word "induced" seems to be overused (in the sense that its meaning does not always seem clear.): induced quotients, induced homomorphisms, induced bundles, etc. So: does anyone know if induced maps can be described categorically, or at least, could someone please explain when a given map between topological spaces induces a map on homology or cohomology.?.
I think there is some underlying algebraic result dealing with normal subgroups(which extends to any subgroup in homology, since chain groups are Abelian.), but I am not too sure of this.
Thanks For any Help.