What is web applications?

Web applications are applications that are opened through browsers and are available on the internet. But how are they developed?

Web applications are divided into two main parts:

1. Front-End: This is everything that the end user sees on the screen. But how are all these designs developed and converted into a language that the browser understands to display them as intended?

Initially, the developer receives the design file from the UI designer to slice it and write the necessary code to make this design appear correctly in the browser. This is done using HTML to build the general structure of the site and to add text and images.

But how does the developer add styles like formatting and colors? They use CSS, which is a language that adds character and identity to the site by enhancing its aesthetic appeal. But is this enough to create an attractive site? In reality, yes, but it can be somewhat challenging, so developers often rely on libraries like Bootstrap, where they use pre-prepared code to complete the work faster and more accurately. We will discuss these libraries later.

Now the front-end is ready, and the developer has transformed the design into web interfaces displayed in browsers. But is this enough to become a professional front-end developer? The answer is no. Why?

Simply because a front-end developer must handle data coming from the back-end and display it on the front-end appropriately. But how do they do that?

Front-end developers use the popular programming language JavaScript by utilizing one of its well-known libraries like Angular.js, React.js, or Vue.js to interact with APIs (which we will explain later). In short, APIs act as the intermediary between the back-end and the front-end.

In summary, a front-end developer must possess skills in the following languages and libraries:

- HTML

- CSS with one of its libraries (e.g., Bootstrap, Tailwind, etc.)

- JavaScript with one of its libraries (e.g., Angular.js, React.js, Vue.js, etc.)

Additionally, they should have various other skills, such as working with font libraries or libraries for adding animations to the site.

2. Back-End: This encompasses everything that happens behind the scenes, which the end user does not see or feel, such as user authentication during login and granting appropriate permissions. But how is this done?

Back-end developers use one of the powerful languages along with its frameworks to interact with databases and perform operations on them. For example, they might use Java with Spring Boot, Python with Django, PHP with Laravel, or C# with ASP.NET, among others, but these are the most common.

A back-end developer must be proficient in the language they are working with, have problem-solving skills, and be good at data structures and algorithms to handle data in the best possible way.

We will discuss both sections in more detail in later articles.