The RF License Agreement grants you the right to use the image in different type of projects including commercial and editorial usages like advertising, publications websites, blogs, presentations, video, etc. There are some limitations of the permitted uses that are well explained in the RF License Agreement.
The files are licensed as Royalty Free. That means that you can use them in as many projects you like and as many times as you need, always by the same user that can use that licensed images for different projects. The moment that the user want to share the image among a group of users you have to purchase an additional license called EXTENDED LICENSE.
There is no expiration date on your rights to use the downloaded files.
For example, if you work in a marketing department of a company, you could use the image for the same project multiple times or for a different project. But you could not give the image to a colleague that works in another department to use them for the other project.
If you need that multiple persons can work with that image you would need no purchase an extended license that would grant that type of usage.