https://www.mediawiki.org/wiki/Manual:Wiki_family#Wiki_Farm

Installing Wikifarm

First

Install the first wiki as normal. For details, see Manual:Installation guide.

Dreamhost no longer offers one-click install for Mediawiki

https://help.dreamhost.com/hc/en-us/articles/217292577-MediaWiki-Installing-and-more

WinSCP — Connecting to your server

https://help.dreamhost.com/hc/en-us/articles/216656067-WinSCP-Connecting-to-your-server

WinSCP-Uploading-to-your-server

https://help.dreamhost.com/hc/en-us/articles/216655867-WinSCP-Uploading-to-your-server

Second

Enable your web server to share your MediaWiki install with all wikis. For multiple (sub)domains, have your web server accept connections from all the relevant domains. For multiple subdirectories, you could use rewrite rules, aliases, or symlinks.

This LISTEN call tells the TCP⁄IP address space that the server is ready to begin accepting connections.

By specifying the correct IP address for each (sub)domain on the DNS server, each domain will point to the same web server.

For multiple (sub)domains, you can use "listen" on the multiple server names. For multiple subdirectories, you could use: rewrite rules, aliases, or symlinks.

When the server is operational after start up, the means of communication in or/and out (ports, sockets...) are open to receive or send requests to other servers.

"Listening" is to wait for a command on an input port and process it. There is general information about servers on Linux, Apache, or others.

In a farm of wikis servers exchange messages to each other. Of course they know each other the configuration of the network for that.