Files, Content, Attachments, Documents etc.
What is the difference between Files, Content, Attachments, Knowledge documents?
Files, Content, Attachments, Documents have always been a mess and are even more of a mess now we have Lightning.
Attachments in Lightning
Attachments are meant to disappear in Lightning but here we are, more than 3 years into Lightning and still it's not advisable to remove the Attachments related lists from most records.
Your Main Appexchange Apps may not work with files yet. Here are the ones I'm working with currently.
Conga
Conga does have a files, and a chatter option at least, but how many Conga implementations are out there that are still saving to Attachments, and you only have Chatter as an option if you want to specify the parent. Oh and at least they allow you to support Versioning of Files and they allow you to attach files to a Merge. So overall not to bad. Here is their overview of Files. Over to me to change ALL my button URLS to use Files (do you know how much I HATE changing Conga buttons and HATE the way Conga does buttons?).