On Xbox 360 Arcade what it have on?

It's impossible to know what's on an Xbox 360 Arcade without more information. To help me tell you, please give me more context:

* What do you mean by "on"? Are you asking about:

* Games: What games are available for the Xbox 360 Arcade?

* Services: What online services are available on the Xbox 360 Arcade?

* Hardware: What are the technical specifications of the Xbox 360 Arcade?

* Do you have a specific Xbox 360 Arcade in mind? Is it yours, or are you asking about a specific console?

Once I have more information, I can provide you with a more accurate answer.