A web application is a computer program that utilizes web browsers and web technology to perform tasks over the Internet. It is usually coded in browser-supported language such as JavaScript and HTML as these languages rely on the browser to render the program executable. Some of the applications are dynamic, requiring server-side processing. Others are completely static with no processing required at the server.

Web apps have several advantages over desktop applications. Since they run inside web browsers, developers do not need to develop web apps for multiple platforms. For example, a single application that runs in Chrome will work on both Windows and OS X. Developers do not need to distribute software updates to users when the web app is updated. By updating the application on the server, all users have access to the updated version.

How is web application different from website?

In layman terms,
- A website is informational
- A web application is interactive

To illustrate the difference, let’s take the example of a restaurant’s web presence. If you visit the site for your local Chinese takeout joint and find nothing more than the hours of operation, a menu, directions from the nearest highway or a static map, and contact information listed then you’ve got yourself a website.

However, if you went out and visited a site like the one for zomato, you would find all the “static” information and then additional functionality. You can make a reservation, view a customized menu that includes prices at your local store, order your food online, or purchase a gift card. This sort of interactivity is specific to a web application and is what differentiates it from a website. Put simply, a web application is a web site that the user can control.

Web Application Architecture

Web application architecture defines the interactions between applications, middleware systems and databases to ensure multiple applications can work together. When a user types in a URL and taps “Go,” the browser will find the Internet-facing computer the website lives on and requests that particular page.

The server then responds by sending files over to the browser. After that action, the browser executes those files to show the requested page to the user. Now, the user gets to interact with the website. Of course, all of these actions are executed within a matter of seconds. Otherwise, users wouldn’t bother with websites.

What’s important here is the code, which has been parsed by the browser. This very code may or may not have specific instructions telling the browser how to react to a wide swath of inputs. As a result, web application architecture includes all sub-components and external applications interchanges for an entire software application.

Of course, it is designed to function efficiently while meeting its specific needs and goals. Web application architecture is critical since the majority of global network traffic, and every single app and device uses web-based communication. It deals with scale, efficiency, robustness, and security.

Typical Flow of a web application is as follows -

  • User triggers a request to the web server over the Internet, either through a web browser or the application’s user interface.
  • Web server forwards this request to the appropriate web application server.
  • Web application server performs the requested task – such as querying the database or processing the data – then generates the results of the requested data.
  • Web application server sends results to the web server with the requested information or processed data.
  • Web server responds back to the client with the requested information that then appears on the user’s display.

Available Technology Stack

What’s the most important thing to consider when you’re developing a top-notch web application? No doubt it’s the technology stack your app will be based upon. The right tech stack is, to a great extent, the key to your project’s success, while the wrong choice of web app development technologies may be a reason for failure.

There are two sides to web development: the client side and the server side. The client side is also called the front end. Server-side programming involves an application (and a backend programming language that powers it), a database, and the server itself.

  • Client Side Programming: Involves everything users see on their screens
    1. Hypertext Markup Language(HTML) and Cascading Style Sheets(CSS):
      HTML tells a browser how to display the content of web pages, while CSS styles that content. Bootstrap is a helpful framework for managing HTML and CSS.
    2. JavaScript (JS):
      JS makes web pages interactive. There are many JavaScript libraries (such as jQuery, React, Preact, and Zepto.js) and frameworks (such as Angular, Vue, Backbone, and Ember) for faster and easier web development.
  • Server Side Programming: The server side isn’t visible to users, but it powers the client side, used to create the logic of web applications.
    1. Ruby (Ruby on Rails)
    2. Python (Django, Flask, Pylons)
    3. PHP (Laravel)
    4. Java (Spring)
    5. Scala (Play)
    6. Node.js
  • Database Management Systems: Your web application needs a place to store its data, and that’s what a database is used for.
    1. MySQL (relational)
    2. PostgreSQL (relational)
    3. MongoDB (non-relational, document)

What is PWA?

The Progressive Web Application(PWA) is a relatively new concept in the mobile and Internet world. Built using Javascript a PWA gives you two for the price of one; a fully responsive website and app-like functionality when on a phone all without having to build and pay for a native app. In the simplest terms, it is a type of mobile app delivered through the web.

Being an “app” does not mean PWA is limited on mobile. They can be implemented on desktop as well. In fact, chances are you have frequently visited PWA before without you even realized that. If you’ve ever browsed Instagram, Pinterest, or Tinder on your laptop, then congratulations! You’ve encountered some of the most successful adopters of PWA on the web.

Service Workers is the name of the technology behind a Progressive Web App, which power its offline capability, push notifications and resource-caching. According to Google, Service Workers are at the core of PWA techniques.

During the Google I/O 2017 presentation dedicated to PWA, it was mentioned that even though web applications on mobile have almost 3 times more unique users compared to native apps.

PWAs are the next big thing, because they have following features -

  • Data-friendly
  • Multi-platform
  • User engagement
  • Security
  • Speed
  • Offline mode
  • Add to home screen

PWAs is better than native apps at -

  • Cross-platform
  • Up-to-date
  • Indexability
  • No need to publish
  • Low development cost

Big names that have adopted PWA -