Web App Architecture: Layers, Components, and Types

Web App Architecture: Layers, Components, and Types

Vitaly Kuprenko
July 28, 2021

Before creating a new web project, choosing the proper web app architecture to succeed is vital. Your choice will define how its elements and functionality will interact and further logic of building the application.

In this post, I’ll explain what web application architecture is, how it works, and what types are there.  

What Web App Architecture Stands For?

Web application architecture is a network of multiple components such as UI, transaction processing control, databases, and others. The core goal is to provide the proper work of all connected elements. 

The logic is quite simple. When you type a website URL into the browser and click ‘enter’, the server gets a request from the browser. The server responds and displays the needed web page. 

All these components make a web app architecture.

How Does System Architecture for Web App Operate?

All applications have two parts — the client-side (front-end) and server-side (back-end).

The front-end is the art of developing web applications. It stands for all elements digital users interact with (buttons, programs, and other features) while using the apps. In turn, the back-end is responsible for processing users’ actions. It manages business logic and makes responses to HTTP requests.

For instance, when you're filling up the form to register on a website, you interact with the client-side of the app. The server-side processes your request and gives access. 

I’ve prepared a picture to demonstrate how web application architecture works.

Web Application Architecture: Layers and Components

To deep dive into web application architecture, it’s essential to learn its primary components and layers. Web apps split their main functions into layers to enable the updating of each layer separately. 

Core Components of Web App Architecture

Web architecture consists of UI components and structural components. In turn, structural components have client-side and server-side.

User interface components

UI components make up the layout of the web application interface. It describes interface elements users are in touch with (activity logs, dashboards, notifications, settings, and more).

Structural components

As I’ve mentioned earlier, these components divide into client and server sides:

  • The client component is built with HTML, CSS, or JavaScript. The programming code is run and converted into the interface by web browsers. Thus, there is no need to adjust the code to various operating systems. 
  • The server-side is developed with .Net, NodeJS, Python, Java, etc. It includes database and app logic. The last one controls the whole workflow of the web app. The database stores users' information (e.g., login credentials).

Web Application Architecture Layers 

There are four major layers of web apps:

  • Presentation layer 
  • Data service layer 
  • Business logic layer 
  • Data access layer 

Let’s consider what stands for each of them.

  1. Presentation layer. PL submits all the needed information to the client-side. Its main goal is to obtain input data, handle users’ requests, transmit this information to the data service, and display the results.
  2. Business logic layer. This layer takes care of correct data exchange. BLL determines the logic for business processes and rules. 
  3. Data service layer. DSL sends data to the Presentation layer. This layer separates business logic from the client-side to provide data security.
  4. Data access layer. This layer facilitates access to data kept in persistent storages (e.g., binary XML file, etc.). Besides, DAL manages CRUD operations (create, read, update, and delete).

Types of Web App Architecture

There are five common web app architectures:

  • Single-page web apps
  • Multi-page web apps
  • Microservices architecture
  • Serverless architecture
  • Progressive web apps

The difference is how web app logic is handed out among the client-side and server-side.

Single-Page Web Apps

SPA means a website or web app that displays the needed information when a user enters the page. The core benefit of these pages is no web pages are reloading. The most famous examples are Gmail, Facebook, and Slack.

Multi-Page App 

Multi-pages apps are a perfect choice for large websites (like Amazon or eBay). Such web solutions update a web page to transmit a significant amount of information between a browser and a server.

Microservices Architecture

For a better understanding of microservices architecture, let’s consider the monolithic model first. 

The traditional monolithic model has three parts: 

  • Database
  • Client-side
  • Server-side.

It implies that all background tasks, including back-end and front-end logic, are made in one codebase. If there is a need to change or upgrade the app components, programmers will rewrite the whole code.

In turn, microservices architecture enables software developers to create an app from the blend of small services. Each part of the app is made and deployed separately. Hence, all components handle their own processes. The services integrate using lightweight APIs.

Microservices architecture is perfect for scalable complex projects (like Netflix, Paypal, Uber, etc.) since each component can be modified without affecting the other blocks. So, for example, if you needed to change the payment logic, you wouldn’t need to pause the web app’s work for a while. 

Serverless Architecture

This approach implies the usage of 3rd parties services like Amazon and Microsoft. 

To maintain a web app on the Internet, programmers need to manage (virtual or physical) various service-related operations such as server infrastructure or operating systems. Cloud providers submit virtual servers that are responsible for managing the distribution of machine resources effectively.

Put simply, if your web app goes through a massive traffic spike your server can’t cope with, the app will continue to work. 

Progressive Web Apps 

The popularity of progressive web apps keeps growing. They’re budget-friendly, have a higher conversion rate than traditional web apps, and are easy to develop and maintain. These PWA are created to perform like native apps and benefit from the features of mobile applications (fast loads, push notifications, offline access, etc.). 

Wrapping Up

The high-quality web application architecture will allow you to scale, change, test, and debug your future web application along with effective development process management.

Vitaly Kuprenko is a technical writer at Cleveroad, a mobile and web app development company in Ukraine. He enjoys writing about tech innovations and digital ways to boost businesses.

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