Database setup

The two database servers that must be set up for Sitecore are SQL server and MongoDB.

Sitecore uses SQL server to store the Master, Web, and Core databases. For xDB, Sitecore uses MongoDB. As of 8.1, it is possible to run Sitecore without xDB, by using CMS-Only mode. If your solution is running in CMS-only mode then you do not need to install MongoDB. You can read more about CMS-Only mode in Experience Manager.

You can find more details on setting up MongoDB for xDB in MongoDB example architecture.