From the Files related list in Lightning Experience, users can upload files to attach to a record while leveraging the rich features and flexibility of Salesforce Files, such as sharing with people and groups, sharing to libraries, and syncing.
Files uploaded to a related list are visible only to those who can access the record where they reside, but those with access to the record can share it further (unless the file is frozen). When a user uploads a file to a record, it is also listed on the Files page, where more actions are available.
To add the Files related list to an object, edit the page layout for that object in Setup. Click Related Lists, and drag Files to the Related Lists section in the order you want.
View Related Files in Lightning Experience
In Lightning Experience, the Files card lets users upload files and shows the most recently uploaded files for the record.
The related files card also links to the full related list of files for that record.
View Related Files in Salesforce Classic
The Files related list in Salesforce Classic shows all the files that have been shared with the record. From this list, users can download, delete, preview, or view details for each file.