There are situations where you don't have a wifi or LAN available but you would like to exchange some files. Then you find yourself copying to a usb stick and giving it to your colleague. You are probably sitting together on the lobby of a hotel, a train, a plane, it doesn't matter, but connecting to the internet or a local network is not an option.
Wi-Fi Direct is a standard to connect with each other without a wireless access point. So, if your two laptops are close enough, you should be able to take advantage of your wifi antennas to transfer data faster than using the usb.
.NET has a bunch of classes to help implementing this. Unfortunately, (IMO) they are all designed to be used from UWP or Windows Store apps, and it is sort of a nightmare to use them from a simple Console application (or a Windows service, which could greatly benefit from this functionality). I'm going to explain how to use the old PeerFinder (available since Windows 8.1) to transfer data using Wi-Fi Direct from a simple C# Console program. Full source code available on GitHub.