What is a "resource" and why so many?

Joplin 2.11.5 (prod, win32)

Client ID: bf7c9ed39cb14cfe8e3dfbc1cb8ebad9
Sync Version: 3
Profile Version: 42
Keychain Supported: Yes

Revision: 3621e25

Note overview: 1.6.0
Simple Backup: 1.0.3
Templates: 2.4.0

I have about 3000 notes. Each has one or two images attached. When I loaded it fresh on a tablet yesterday it spent a lot of time (hours) loading the 40,000+ resources.

What's a resource? Looks as if each word in the notes counts as a resource.

Do you use web clipper frequently? If so each and every graphics element of a web page is captured and saved as a separate file in the "resources" folder.

I wonder if there's a limit on how many files you're allowed to store in certain public clouds such as Dropbox or OneDrive which Joplin can sync with. I remember a total number 100,000 files mentioned somewhere else in this forum, but I'm not sure if this a fact that can be documented anywhere.

I do not use web clipper at all nor do I use any cloud sync. All my data resides on my own NAS (Synology) on my local network. Note history is set to one (1) day and while I may add a few notes daily, I rarely delete any and rarely change any. I do keep a half-dozen devices synced to the NAS data whenever I get around to it but these are used simply as backups and don't ever make any changes to existing notes.
Of the 2400 or so (I just added them up) about 2300 of the notes have two images each with the occasional one having three. The balance of the notes are text only.
So I don't know where these 40,000 resources came from. I have just done an "Export All" and tomorrow plan to wipe everything and reload, something I haven't done for a few months. Hopefully that will get rid of a few "resources."

Try this tool to check unused resources

docs ref