Re: How can I see when new games are added to the

How do they do that? What does SHA1, MD5, ird, dkey and SFV files do?

Well for cartridge based games this site uses the No-intro database and you can see the most recently added items (for example NES) by going here and changing the "Operation" drop down to "New items":

https://datomatic.no-intro.org/index.php?page=news&s=45

For disc based games it uses the Redump database which posts their most recent dumps here:

http://redump.org/discs/sort/added/dir/desc/