Installing Multisite
You don't so much install Multisite as activate it: first you install WordPress in the normal way and then activate Multisite. But before doing so, you need to decide how your network will be structured—using subdomains or subdirectories.
Multisite structure – subdomain or subdirectory
You can use one of the two structures for URLs for the sites on your network, but you have to choose one before you start:
Using subdomains means that each site will have a URL such as
http://site1.yoursite.com. If you're planning to let people create their own site, you'll need to have wild card subdomains activated for your hosting. Find out more about wild card subdomains at https://codex.wordpress.org/Configuring_Wildcard_Subdomains.Using subdirectories means that each site will have a URL such as
http://yoursite.com/site1. You can't choose this option on an established site that you're converting to a network as it may cause clashes with URLs already created in your site.
What you choose...
