You are going to have to be more clear about what you mean.
I will assume you have the fairly common setup where you are using a router to access the internet. Both machine connect to the router and they can then talk to each other. You should be able to use microsoft file sharing if that is your goal.
They are both connected to the same router. The desktop is connected directly to the router by a Cat 6 cable. The laptop is connected wirelessly to the router. THEY DO NOT SEE EACH OTHER. I go and click on the network, and neither one sees the other.
They are both connected to the same router.
The desktop is connected directly to the router by a Cat 6 cable.
The laptop is connected wirelessly to the router. THEY DO NOT SEE EACH OTHER.
Connect both with ethernet cable to router.
Router may have wireless client isolation set up. Then wired and wireless devices can not see each other.
Also both your devices need to have network discovery enabled, to be able to browse network.
(Settings/Network&Internet/Advanced Network Settings/Advanced Sharing Settings/Network Discovery)