how does apple send my app to different iOS devices

I want to find out what is the common method of targeting different iOS devices. Specifically regarding textures, and can textures be filtered so 4x is sent to one device, and 2x is sent to others.

For example, we have been making a game mainly designed for iPad new (retina), but also looking to release for other iPads, pods and phones(4/4S). Texture swapping in the game for different resolutions is working fine.

My question is : when I submit the app to apple, does it send the same package to all devices? Does the device load all the texture sizes? Is there an in-house way of targeting the iPad (3rd generation) to only receive the 4x textures, and likewise all the other supported devices to only receive the 2x textures? Or do we have to submit different packages for different devices?

This may sound noobish, and indeed this will be our first app store submission, I was hoping someone who has done the process and understands it would be able just to give me some advice, or a link to some reading material, would be very much appreciated.

I have this question on the forum, but have not had any comments. . I can delete this question if someone could simply point me in the right direction to find out how packages are distributed between devices. Thanks.

You don’t download an app for a device; you download for a device family (iPhone/iPod touch or iPad), or you get a universal app. Go play with the App Store in iTunes and see for yourself.