Howdy Semperfi and welcome to the forums!

given the right software, you can set up your system so the keys you press while on one wow.. get sent to the other, this can come in handy if you have F5 bound to a macro on your healer to heal your tank.

here is a basic, step-by-step example using keyclone:
FAQ: step-by-step basic keyclone setup

this is just the basics... but it starts you down the road.

check this post for a series of links that might be helpful, along with some cool screencaps:
Bought Keyclone, and not getting maximizer set up correctly.

if you have any other questions, please feel free to drop me a note. (the faithful always welcome)

have a great night,

-- Rob