Databases can be much more than just managing your contacts. A few common uses for databases are:
Contact Management
Keep up to date information of all your potential clients, your existing client accounts and suppliers
Stock control and pricing
Your web site can display to your customers a price of an item and if it is in stock for immediate dispatch.
Invoicing
When a client orders an item, an invoice is created automatically, the prices are inserted along with any discount structure that applies to that client, then the item is removed from stock