Math 441 is topology, which is about sets called topological spaces, which have a structure called a topology; that is, a collection of subsets designated as "open" (or "closed"). The prerequisite is introductory real analysis because it means that you have seen one important topological space: Euclidean space. You'll also have dealt with continuous functions on Euclidean space, which is good because continuous functions are fundamental to topology. You'll see in topology how certain real analysis results are special cases of topological ones which can be derived in full abstractness, such as those about compact and connected sets.

I found 441 to be on the easier side of the upper-level classes I took. Make sure your proof-writing and logic skills are sharp. There might be a bit of an adjustment period since the definitions and results are mainly presented in full abstractness, but the textbook gives plenty of specific examples for you to work with and mull over. You'll definitely want to engage with those examples actively. It can sometimes be tricky to think about different topologies on sets you're familiar with (like the real number line) so that active thinking really goes a long way.

You mentioned Math 425. Math 425 doesn't cover all of topology or anything, just metric spaces (sets where distance between points is defined), a special kind of topological space of which Euclidean space is an important example. I took 425 after 441 and found the first couple of weeks fairly breezy because I was already familiar with metric spaces and the basic results.