Drum roasters roast a bit slower than air roasters. The drum roaster typically roasts coffee between 10-18 minutes. These machines are common with specialty coffee roasters because they have a high level of control over the main variables of roasting coffee: time and temperature.
A roast profile is what roasters use to determine when to change certain variables with a drum roaster.
The other most common type of roaster is an air roaster, which uses airflow to rotate coffee beans while heating.