When customizing your portal, you'll probably need static files (images, font files) to be available throughout the platform. This page will enable you to do just that: upload files to your platform so that you can link to them in the stylesheet or within your pages.
You can access this page through the link in the back-office navigation bar.
You will be able to upload files that do not exceed 500kB. If you need to host larger files, you will have to resort to an external file-hosting service.