Correct. A wrapper.
See here for much, much more.
https://docs.pyrevitlabs.io/reference/pyrevit/revit/db/
Similar to Revit Pythion Shell. There you don’t have to import uidoc or dbdoc as it is already done for you.
I can’t really comment on speed differences. I tend to rely directly on .Net and the API. More out of habit and coming from C# and VBA.