Our home has one dishwasher. I would like to add another dishwasher; total 2 dishwasher hooked up to the same sink.

Reading online it seems that there is a possibility for "back pressure". Is this correct and what exactly is that? Also, would there be a reason that I could not run both dishwashers at the same time? Are there any other possible problems to having a second dishwasher installed?

Thanks for any guidance!