WordPress Multisite is a powerful feature of WordPress that allows users to create and manage multiple websites using the same WordPress installation on their server. In other words, you can manage several different WordPress websites from a single control panel. This feature can be added to an existing or newly created WordPress site, and it allows users to create a network of websites in a single WordPress installation. To activate WordPress Multisite, you need to add a few lines of code to two files in your WordPress installation.
After that, you can create sites on your network. The existing site stays there, with its URL unchanged, while new sites are added at the top. All websites on a multisite network share primary files and databases, allowing network administrators to manage all websites on a network from a single WordPress user account. When you use Multisite, each site will have its own administrator, but the main site will have a “super administrator” who will also have access to all the content of the subsites.
If your multisite network grows, you'll need to be aware of the amount of server resources your site uses, as well as the maintenance of your database. All multisite websites share the same domain name, which is the domain name of the original WordPress website. What differentiates WordPress Multisites from individual WordPress installations is the back-end configuration. If you're hosting multiple sites with different accounts, you'll need to install WordPress for each site separately.
On the other hand, when using Multisite, there is only one set of core WordPress files and only one copy of each theme and plugin. Using a multisite network to host the sites of multiple groups will save money and increase the opportunity for those groups to connect to each other. We recommend that you work with a WordPress consultant who is an expert in scaling managed WordPress hosting on Multisites. For many WordPress users, this setting is preferable to a collection of dozens of separately managed websites with minimal oversight.
Multisite networks concentrate network control on one or a pair of super administrators, who are responsible for adding new users and assigning permissions. There are differences between the administration screens and their use, between the files of the WordPress installation and between the files in the database. In addition, creating content and adding everything to a new multisite can be a slow process, especially if any of the websites in your multisite will start from scratch.