The Simplify Suite uses an SQL database to store all of the configuration data for the users, groups, and OUs in the environment. During the Simplify Suite install, a 'Simplify' database is created on the SQL or SQL Express server instance, and all Suite configuration data is stored here. Since the database is only holding mainly configuration data, it should not grow too large in size (an average would be around 20-40 MB). Simplify Profiles, however, does store any saved registry information in the database for each user, which can make the database size increase depending on the number of users in the environment.