Is it possible to run a Minecraft server on a laptop, and play it on a PC?

So I thought I might give my PC a little less stress, so I thought "Oh wait. I have a laptop"
The laptop has 4GB of RAM and I try to run the server but sadly it says

"perhaps a server is already running on that port"

What does this mean exactly? Will I need to delete the server off my PC altogether and have it stay on the laptop? How exactly will I work this to work on my laptop and play the game without lagging like hell on the PC

;Note; I have the server up and running except it just says that port issue

FYI: a PC is another name for a laptop. PC stands for Portable Computer, (aka a laptop).