- Gathering information from the user
- Sending the user information to the business services from processing
- Receiving the result of the business services processing
- Presenting those results to the user
- Receiving input from the presentation tier.
- Interacting with the data services to perform the business operations.
- Sending the processed results to the presentation tier.
Data Service Layer
- Storage of data
- Retrieval of data
- Maintenance of data
- Integrity of data