How are bots detected?

Purely from a coding/programming interest, I was wondering how Warmane detects if players are using a bot? Is it simply recognizing behaviors in-game or it is more detailed than that, such as detecting if the user is running 3rd party software that interferes with the game? Or is there no way of doing this at all, and it's just if someone reports that the user is botting? Am interested in nerdy stuff :3

I wasnt sure what to categorize this as, so im sorry if this is the wrong place for this question :c