Inlet valve to share between faucet and dishwasher
There are adapters you can screw on that give an additional tap for the dishwasher. The size needed for the dishwasher connection is fairly standard (3/8 compression thread) as it is common to run 3/8" o.d. copper tubing or a braided stainless flex connector with that same thread.

What is NOT standard is the existing valve's outlet size (it can be any one of, like 4 different sizes). You will need to either have someone with experienced eyes take a look at your existing valve, or remove the existing supply line and take it to the plumbing shop with you.