Firefox for Android Beta Isithangami Sokwesekwa

Forgive my ignorance, but what exactly are collections? I recently downloaded Firefox Nightly for Android and set up a collection of Addons so I could install addons that are not supported on Firefox mobile for Android. I still don't understand what collections are though, and in the process of setting one up, I think I read that all collections are public and can be accessed by anyone through the URL (or google search?). If so, what do they see? Do they see just the addons I have in the collection, or do they see the private data from those collections, such as my settings, the sites I visit, my browsing history, and any other sensitive information?