The master device contains the master, model, tempdb, and sample databases.
master – controls the operation of Adaptive Server and stores information about all users, user databases, devices, objects, and system table entries. The master database is contained entirely on the master device and cannot be expanded onto any other device.
model – provides a template for new user databases. The model database contains required system tables, which are copied into a new user database with the create database command.
tempdb – the work area for Adaptive Server. Each time Adaptive Server is started the tempdb database is cleared and rebuilt from the model database.
The sample databases are stored on the master device at installation, but should be moved to a user-defined device after installation.