Presentation, application, and data processing. Presentation, application, and data processing are the three logical and physical computing tiers that make up a three-tier architecture. A three-tier architecture is a type of software architecture that separates an application into three layers or tiers that run on different servers or machines. Each tier performs a specific function or role and communicates with other tiers through well-defined interfaces. The presentation tier is the user interface and communication layer of the application, where the end user interacts with the application. The application tier is the logic or middle tier of the application, where data is processed using business rules. The data processing tier is the data or back-end tier of the application, where data is stored and managed12