multiplexer(mux) - allows multiple people to use the same TTY
(we did this with screen and also opened up different windows)
when using screen (ctrl+a) + ? will show shortcuts

needs to handle, either multiple input/output from/to a singular input/output
-  google docs is an example of multiplexer
-  VNC is technically multiplexer

command to show the network connections
ss -taln 

apache is the most commonly used web server
iis - internet information services from microsoft is another web server
nginx - another commonly used web server

common convention for software developers for their repository pages is to use git.domain.com

webpages are usually just a file or a folder

can have many websites hosted from one domain
a website has to have at least one domain, but can have multiple subdomains. 
apache was default for port 80 on the domain for gogs

used a2enmod, enabled modphp, enabled modproxy, a2ensite to configure site config files