Slash Shop – /shop
Seems to be canonicalised to home by default and uses the same template. Unsure what its original use was. Seems like a legacy holdover of some sort.
/collections/all – the all products page
This is a meta-collection that literally contains ALL products on your site. Even products you may not have included in other collections. If you want to control what is allowed in this page, you’ll need ‘override’ it by creating a collection with the /all handle.