They are different version with this one being Beta 5 and the steam version currently (as of comment) being Early Access 30, This includes steam workshop support and a ton of different mods as well as more vanilla gamemodes and maps. I started off playing loads of beta 5 really enjoying it and eventually upgraded and bought the steam version because of how much i enjoyed the beta.
I still forget people play this game on itch.io... Also, I recommend buying the game it's absolutely worth every cent. I have about 122 hours on it and the itch.io version was how I was introduced into Ravenfield. The memories I have made on this itch.io version will forever have a place in my heart.
