Most components in ATG can be classified into one of the following categories:
- Service: A component that provides functionality on which one or more systems depends.
- Form Handler: A component to validate and manage form input data.
- Servlet Bean: A droplet to handle page display logic.
An example of a service component is a scheduled service. Your server-wide application may have tasks that need to be performed on a periodic or recurring basis. For example, a component in the application may need to clear a cache every 10 minutes, send email at 2:00 AM every day, or rotate a set of log files on the first day of every month.