Yes, you can use SSI with Mochahost.
This is the ability to include files from the server inside an HTML document by placing tags in the HTML file that link to those files. Using server-side includes makes it unnecessary to include multiple copies of the same information in the HTML file. This makes it easier to work with the same information used on multiple pages, such as a navigation bar.
When using SSI on the Mochahost server, it is necessary to designate SSI files with the extension ".shtml".