As the name implies, it's the core process that provides the connectivity to your iPad and similar Apple mobile devices. Restarting it may restore connection to your iPad, if it's not being recognized in iTunes now. If your iPad is being recognized and is working correctly with iTunes, you should not muck with AMDS; there's almost certainly no need to, in any case. But it's unlikely to cause problems unless iTunes is in the midst of syncing with your iPad.
Regards.