If wanted, you can also create categories for support requests. Then when someone submits a support request, they can also select which category the request pertains to. Every category can be assigned to a different department, helping ensure all support requests get to the correct people. You can create categories through the Setup->Category Settings menu.

When creating a category, you are asked for a category name, and department. If you select a department, only support techs assigned to this department will see new support requests assigned to this category. For example, you can create a Billing category, which is assigned to the Billing Department. Then, only the Billing Department will see new requests submitted under the Billing category. Please note, this is an optional feature, and you do not need to create any categories.