A little trolling going on in that Wikipedia page. It captions the Cambridge photo as "Three-decker", where locals would call it a triple-decker. It then captions the Worcester photo as "triple-decker", where locals would call it three-decker.

Those look a little like the Mansion Blocks we have in London - https://welcomehome-london.com/architecture/mansion-blocks/

Yep, that's what tons of houses outside of the immediate city center of Boston look like.