Each project and component can have its own set of files, allowing you to organize your files into categorial or hierarchical groups, like datasets or studies. Each file has a unique, persistent URL so that it can be cited or linked to individually.
Individual files uploaded to OSF Storage must be 5GB or less. Larger files can be stored in an add-on.
Open your project, then click the Files tab.
The "Files" page will appear.
Select a storage provider (e.g. OSF Storage, Dropbox, etc.).
Then click the Upload button in the toolbar, and select the file(s) from a dialog box.
Or, drag and drop the file(s) from your computer into the storage provider.
The file(s) will be added to your project.