Can someone identify this part? It's from the page of Home Depot.
It looks like a heavy-duty bracket.
This is a "tension tie" used both to tie joists to the house through the ledger, and to mount posts on the outside of the rim joists. There are different versions of these but most tie to an inside joist with nails or screws, then to the post (or bracket inside the wall) with a bolt.
Example Simpson version:
And here's one installed, seen from the face of the tie: