Scrapbooking and Junk Journal Overlap

Since joining this subreddit, I wonder what this community considers something to be strictly traditional scrapbooking and junk journal.

I might be one of dozens to have asked this. Though after reading a bit of ‘The Ultimate Practical Guide to Scrapbooking’ and reading the sub reddit flairs and tags, I naturally wonder about this distinction and how strict it's followed here.

Are scrapbooking pieces strictly only about keeping photos;
and junk journals about starting off from ‘junk’ when building a piece?

Just curious, as I was introduced to scrapbooking via IG and YT shorts.