How to create a virtual local area network between two linux computers?

Question

linux

There are two computers on ubuntu with Internet access. It is required to create a local network with the ability to share files. How can you organize a network?
UPD:
computers are far away

Answer 1

VPNs are made for this. Connects branches of organizations into a single network

Answer 2

Set up a network through hamachi.

Answer 3

Connect 2 computers to 1 router.

Answer 4

The easiest option (aka 5 minutes)

1. Make sure you have a static address
   
2. If it is not there, register the name on https://www.noip.com and set up dynamic update
   
3. Forwarding 22 ports on your routers
   
4. Use sshfs to mount directories on your drives.
   
5. Ready.