Another n00b question: What are "all the cool things that ocaml can do"?

I only saw rather simple typing examples, which didn't seem much different from what TypeScript can do.

On the other hand I read often that ocaml doesn't have runtime errors, which I certainly get with TypeScript.

This is a good overview I think, although it doesn't get into specifics: https://realworldocaml.org/v1/en/html/prologue.html#why-ocam...

Of course the rest of the book is a great read too if you're so inclined.

OCaml does have exceptions at runtime (eg if you try to take the maximum of an empty list), but generally your programmes won't have type errors at runtime.