DayZ is described as 'The post-soviet country of Chernarus is struck by an unknown virus, turning the majority population into frenzied infected. Fighting over resources has bred a hostile mentality among survivors, driving what’s left of humanity to collapse' and is a Survival Game in the games category. There are more than 10 games similar to DayZ for a variety of platforms, including Windows, Steam, Mac, Linux and Android apps. The best DayZ alternative is Rust (Game). It's not free, so if you're looking for a free alternative, you could try Garena Free Fire or Unturned. Other DayZ like games are Metro, Escape From Tarkov, State of Decay and 7 Days to Die.
Freefire is a battle royale not a survival game