model database is a template on which all user-created databases are based. All databases must contain a base set of objects known as the database catalog. When a new database is created, the model is copied to create the requisite objects. Conveniently, objects can be added to the
model database. For example, if you want a certain table created in all your databases, you can create the table in the
model database, and it is then propagated to all subsequently created databases.