What does this mean that stream must be running to play this game

It is not Stream, my friend, its Steam, and its a direct - to - drive game mainframe, i.e. you buy a game and download it. but since you dont even know how to spell steam properly you propably didnt do it and you got a game that is FROM steam, steam version, and needs steam running to check for piracy. In laymen's terms, you didnt crack the game properly.