Hi Clearsky Thank you for your excellent question, I hope I can help. They are all designed to help you get back sites you have visited before, but they do it in different ways. Top sites are markers on the home screen for easy access. Simple and easy to find. Bookmarks are the normal bookmark feature. You can organise them in folders and (currently unlike the other two options) you can sync them to another copy of Firefox (such as on a laptop) Collections are a new thing with the new Firefox for Android. How are Collections different from bookmarks? They’re really not so different, but you could think of Collections as more front-and-center tab organization around a theme. Tabs stay nested in a Collections folder for tidy storage and viewing on your home screen. Firefox Collections can be easily created when you have the need and then deleted when you no longer do. You can read more about Collections at https://support.mozilla.org/en-US/kb/collections-firefox I hope that this helps.