"At one point in time Atari was a household name like Coca-Cola, Band-Aid and McDonalds. Now in the Sega/Sony/Nintendo generation many only know Atari as that "game company in the 80's that did Pac Man or something". Atari's history and its accuracy are quickly being lost as each new game console and computer system is introduced...." — About the Atari Museum
If you think that the old games are from the Genesis or the SNES, then Atari is older than old. The end of Atari was many years ago. (Atari still exists, because someone bought the Atari trademark and copyrights. If I believe the internet, then the new owners had small interest, and literally put Atari history in the trash.)
The old Atari video game systems were the Atari 2600, the Atari 5200, the Atari 7800, the Atari Lynx and the Atari Jaguar (or Jaguar 64). Atari also made computers, arcade games (like Pong) and miscellaneous other things.