I know this is a very basic question, but let me be more specific. Suppose that, for definiteness, $M$ and $N$ are differentiable manifolds. What means that they have the same topology? Does this mean that there is an homeomorphism $f\colon M\to N$? I know that such homeomorphism implies that $M$ and $N$ can be equipped with "equivalent" topologies but, is there a map more general than an homeomorphism that "preserves" the topologies? For example, if there exist a map $h\colon M\to N$ such that $h$ is an homotopy equivalence, then $M$ and $N$ have the same topology?
My final question is: Suppose that for $M$ you can find an atlas with a single chart, but for $N$ the minimal atlas has two charts. Can they ever have the same topology? In that case if they have the same topology it cannot be because there is an homeomorphism $f\colon M\to N$, because then you could use it to find an atlas with only one chart for $N$.
Thanks.
Saying that $X$ and $Y$ have the same topology means that $X$ and $Y$ are homeomorphic to one another.
If $M$ admits a one element atlas, then $M$ is an open subset of $\mathbb{R}^n$ for some $n$. If $N$ does not admit such an atlas, it cannot be homeomorphic to $M$.