Three-tier architecture in web development refers to a specific design pattern that divides an application into three interconnected layers or tiers: presentation layer, business logic layer, and data layer. The presentation layer, also known as the user interface layer, is responsible for displaying information to the user and collecting input from them.

This layer typically consists of web pages, forms, and other elements that users interact with.

It focuses on the visual aspects of the application and ensures a seamless and intuitive user experience. The business logic layer, also known as the application layer, acts as the intermediary between the presentation layer and the data layer.

It contains the core functionality of the application, including algorithms, calculations, and rules that govern how the application operates.

This layer processes user input, performs necessary operations, and generates output to be displayed in the presentation layer. The data layer, also known as the storage layer, is responsible for managing the application's data.

It stores and retrieves information from a database or other data storage system.

This layer ensures data integrity, security, and efficiency by handling data manipulation, storage, and retrieval operations. By separating the application into these three distinct layers, three-tier architecture promotes modularity, scalability, and maintainability.

Each layer can be developed, tested, and modified independently, allowing for easier updates and enhancements.

This architecture also enhances performance by distributing the workload across multiple layers, improving overall efficiency and responsiveness. Overall, three-tier architecture is a widely used and effective design pattern in web development that helps create robust, flexible, and user-friendly applications.

Its clear separation of concerns and logical organization make it a popular choice for building complex and dynamic web applications.