It is used much like Homegroups was but is better. Homegroups has always had an issue for many and the pros use Workgroups for just that reason.
On a network,(a Home network will be used here), first make sure that all of the networked computers have an admin login with EXACTLY the same username and password. If they don't create one. Once that's done, on a wired "main" computer using the admin account mentioned earlier, open the Control Panel, then the "System" icon, then the "Advanced system settings" link on the right, then the "Computer Name" tab. Select the "Change" button next to "To rename this computer or join its domain or workgroup". Once there, select and create a workgroup name and click OK. Wait for the "its done" message and restart your computer. Now login to all the other computers on the network, using the same EXACT admin login from the first computer and do the same thing.
You should now be able to see the other computers in the "Network" icon on your desktop or in the left hand pane of File Explorer.
Hope this helps.
I reluctantly started using Homegroups, because that was 'the way' and supposedly simplified sharing folders and devices. OK, so I made the change, now I try to use it, and it's gone! Between Windows 10 builds 1709 (where it worked) and build 1803, it has disappeared. I had a chat with Microsoft, and they confirmed this, but I've got to wonder why. So now we're back to sharing folders and the NET USE command. Progress?
When I say disappeared, the Homegroup service is gone, along with trouble-shooting, and its entry in the left pane of file explorer. Gone!