it's a file host. you might be from the recent age where you don't need file hosts because each social media site you go to does it's own hosting of anything you want to share.
Except flash .swf files. In example.
most social media allows hosting pictures audio and video these days, and windows and google have spy software which allows you to mirror all files on your computer on their server(so they can see everything you have on your computer) they call that an "online backup" and "file sync", for such users you can literally just share any file on your computer with anyone online, the problem is then hackers know everything on your computer. So if you are new to the internet the concept of needing a file host may be completely non-sensical to you.
A File Host was used primarily in the old days of the internet (and still today to a decent extent by real web developers who actually have a brain) to upload individual files from your computer as you want to (without sharing everything, and without syncing!) so that you can then share the single file with other users on the internet.
If the file is Text OR Media, such as a picture, audio, video or flash .swf; if you upload it to a file host, the file host will give you a share link, when you give someone the share link and they open it in their browser they are instantly able to see and/ or hear the text or media.
thats what file hosts are for.
This specific file host allows direct hosting of flash .swf games etc. which today is rare, not many allow it. this allows a user you share a flash game with someone else via link, and also allows them to put flashes on their webpage.
Any file can be hosted directly, so long as you have a reader installed in the browser so it can display it. if not though it's hosted directly you will be given a download prompt asking if you wish to save the file.
Other such files that could be hosted directly in the past for gaming are Unity3D game files (which are usually huge), and Blender3D 2.42 game files (as theres actually a webplayer addon for that (doesn't work on later blender games though ~). most file hosts no longer allow these files, infact I've yet to find one that does (catbox doesn't, this was just an example).