The document explains multi-tier architectures in software, focusing on a common 3-tier model comprising a presentation layer, application layer, and data layer, each performing distinct functions. It highlights the benefits of this architecture, such as ease of maintenance, scalability, and risk mitigation. Additionally, it provides examples of technologies and frameworks used within each tier and references for further exploration.

1. Multi-tier Designs in Software
Tharindu Weerasinghe
www.tharinduweerasinghe.com

2. What is a Tier?
• We categorize the main parts of an enterprise
system into sections.
• Those sections are called tires.
• Normally there are 3 tier architectures in many
enterprise applications.

3. 3-tier architecture

4. * A Presentation Layer sends content to browsers in the form of HTML/JS/CSS. Brows
engines can understand them and render...
e.g. This can be done via frameworks like React, Angular, Ember, Aurora, etc.
* An Application Layer uses an application server (like JBOSS, Apache Tomcat)and
processes the business logic for the application.
e.g. This can be written in Java, C#, C++, Python, Ruby, etc.
* A Data Layer which is a database management system that provides access to appli
data.
e.g. This could be MSSQL, MySQL, Oracle, or PostgreSQL, Mongo, etc
3-tier architecture

5. 3-tier architecture
A sample a design diagram of a 3 tier application based
on PHP

6. 3-tier architecture
A sample a design diagram of a 3 tier application based on C#

7. 3-tier architecture
A sample a design diagram of a 3 tier application based on Java

8. Little bit of on Web and Application Servers.
Web server: serves content to the web browsers via HTTP
protocol. (Apache web server, IIS, nginx)
Application server: hosts and exposes business logic and
processes; acts as the facilitator between the data layer and
the presentation layer.

9. 3-tier architecture
Why do we need tiers in enterprise software?
* Easy to maintain
* Easy to update
* Easy to scale
* Risks can be mitigated easily

10. References (with many a thank)
• https://stackify.com/n-tier-architecture/
• https://www.jinfonet.com/resources/bi-defined/3-tier-architecture-
complete-overview/
• https://stackoverflow.com/questions/13786549/how-to-implement-3-tiers-
architecture-in-c-sharp
• https://www.izenda.com/blog/5-benefits-3-tier-architecture/
• http://www.cardisoft.gr/frontend/article.php?aid=87&cid=96
• https://stackoverflow.com/questions/936197/what-is-the-difference-
between-application-server-and-web-server
• https://www.javatpoint.com/server-web-vs-application