Three-tier Architecture: What is it?

The user interface, or presentation tier, the app tier, where data is being processed, and the data tier, where the app’s associated data is kept and maintained, are the 3 physical and logical computer tiers that make up the well-known three-tier architecture.

One of the major benefits of three-tier architecture is that each tier may be built concurrently by a different development crew and can be upgraded or expanded as necessary without affecting the other tiers because every tier operates on its own infrastructure.

The standard architecture for client-server applications for many years was three tiers. The majority of three-tier programs today are candidates for modernization utilizing cloud-native tools like containers and microservices and cloud migration.

Three Tier Architecture Example

Application Tier

The application's core is the application tier, sometimes referred to as the middle tier or logic tier. In this layer, data gathered in the presentation tier is processed using business logic or a particular set of business requirements, sometimes in comparison to data gathered in the data tier. The application tier may also add, remove, or modify data in the data tier.

The application layer often uses Java, Python, Perl, Ruby, or  PHP for development and uses API calls to talk to the data tier.

Presentation Tier

The application's communication layer, user interface, or presentation tier, is where end users engage with the software. Information presentation to and data collection from the user are its primary goals. This top-level tier can function, for instance, on a graphical user interface (GUI), a desktop application, or a web browser. Tiers of web presentation are often created with HTML, CSS, and JavaScript. Depending upon the platform, a multitude of languages can be used to create desktop apps.

Data Tier

The information processed by the app is kept and handled in the data tier, frequently referred to as the data access tier, database tier, or back-end. This could be a NoSQL database server like CouchDB, Cassandra, or MongoDB, or a relational databases management system like  MySQL, PostgreSQL, Oracle, MariaDB, Informix, or DB2 server.

All communication in a three-tier app passes through the app tier. Direct communication between the data tier and presentation tier is not possible.

Benefits of Three Tier Architecture

To reiterate, the main advantage of a three-tier design is the physical and logical separation of functionality. The server platform and operating system that best meet the functional needs of each tier, such as a web server, application server, or database server, can be used to run that layer. Additionally, each tier operates on at least one physical or virtual dedicated server, allowing for the customization and optimization of its services without affecting those of the other tiers.

Added advantages over one- or two-tier architecture include the following:

● Accelerated development:  A firm may release the application to the market quickly and developers can utilize the most up-to-date and effective languages and technologies for each tier because various teams can create each tier concurrently.
● Greater scalability:  As required, any layer may be scaled autonomously of the others.
● Increased dependability:  The accessibility or efficiency of the other tiers is less likely to be impacted by an outage in one layer.
● Enhanced security