What are Frontend and Backend: Differences and Languages

When you use a web platform, far more things happen behind the screen than you might imagine. All the components of the application interact to make the final product work—the one the user interacts with.

The parts that make up a website are typically three:

• Frontend
• Backend
• Data storage

But what are the differences between frontend and backend? What does data storage mean? Let’s go into detail in the next paragraphs.

What is the frontend of a website

The frontend is the visible part of a product. In practice, it includes everything the user sees and directly interacts with: buttons, content on the page, animations, and so on.

The frontend developer works closely with design. The designer defines which flows should be present—for example, what happens when a button is clicked—and how all the elements on each screen should look, and the frontend developer reproduces them in code.

In addition, the frontend also interacts with the backend, making the necessary calls to retrieve, display, and modify the data the user needs.

Not just visuals: what a frontend developer does

It’s not only the visible part of the digital product that falls under the frontend’s responsibility. Its tasks also include:  

• Passing user-provided information to the backend. Example: when a user fills out a form to create a profile, the frontend sends that data to the backend so it can be created.
• Orchestrating data flows. It determines when data should be requested from the backend, when it needs to be updated (for example after an edit action), and, when necessary, performs an initial validation. Example: when a user enters an email address in an invalid format, it flags it.
• Performing an initial layer of checks on operations that are not allowed for the user. This can happen in various ways: disabling buttons, redirecting to a different page, or showing an error message.

Which languages are used in the frontend  

The basic knowledge of a frontend developer includes three elements:

• HTML, the standard markup language for the web. It is a standard created by the World Wide Web Consortium that provides the basic visible elements on the page.  
• CSS, which is used to style elements on the page. It defines, for example, the color of an element, whether it has a border, and its dimensions.
• JavaScript, the programming language par excellence for the web, which makes elements on a web page interactive.

On the other hand, in practice today these three elements are rarely used in their “pure” form. Instead, developers use frameworks, libraries, and other development tools such as:  

• React  
• VueJS  
• Angular  
• NextJS  
• Tailwind

These tools make it easier to manage the complexity of a real application, and also help speed up work—for example by reusing components across different parts of the platform.

What is the backend: the hidden side of your application  

The backend is responsible for performing operations that are not directly visible to the user. The frontend conveys the user’s implicit and explicit requests, but it is the backend that actually executes the necessary operations.

Its action takes place “behind the scenes.” It is responsible for connecting the visible part that the user interacts with (the frontend) with the stored data (the database), serving the necessary data and manipulating it on request.

What a backend developer does

The backend does not simply retrieve and manipulate data. Rather, its role is that of a true control center, coordinating every operation. Each request is interpreted, validated, and turned into a concrete action. It is the layer that ensures everything happens according to the rules defined by the system.

Among the tasks of a backend developer are:

• Executing the operations requested by the frontend. This also includes providing an explanatory response when the operation fails. Example: if a user requests to view a product on a page, the backend will return all the data related to the product, such as name, description, image, and price. If this is not possible, the backend will return 404 if it cannot find the item, 403 if the user is not authorized to view it, and so on.
• Inserting, retrieving, updating, and deleting elements stored in the database. These are the so-called CRUD operations (Create, Read, Update, Delete), the basic operations that can be performed on data, which also correspond to HTTP methods.
• Checking that the user has the necessary permissions to perform the requested operation. Example: when a user tries to edit their company profile but is not an administrator, the backend prevents the modification.
• Managing background processes, such as sending scheduled emails and timed notifications, synchronizing data, and renewing or expiring subscriptions.

What is the difference between backend and back office?

A typical issue backend developers face is that, precisely because their work happens behind the scenes, those outside the field often don’t clearly understand their scope.

So, is the back office somehow related to the backend? In a sense, yes: a back office very likely has a backend behind it, which allows data to be viewed and manipulated. But at the same time, it also has a visible and interactive part made up of the frontend.

A back office is defined as a platform (or a section of a platform) that is usually accessed through authentication and allows modifying data visible to other users.

Let’s look at a concrete example: in a blog, the section where the author can add new articles, edit content, and add tags and images can be considered a back office.

But this back office is itself built with a frontend, which among other things displays the text field where the author writes the new article, and a backend, which ensures the author can only edit the articles they are allowed to and keeps track of saved text, edit dates, and so on.

Ultimately, not only backend and back office are different things, but they also belong to different categories: one is used to build and run platforms, while the other is a type or section of a platform.

Which languages are used for backend development  

How is a backend actually built? A backend can be written in different languages, among which the most popular and widely used are:

• JavaScript, or even better TypeScript, very popular thanks to its use with NodeJS. In full-stack applications, it allows using the same language for both frontend and backend.  
• Python, widely used in AI projects and those involving large amounts of data processing.  
• Java, historically popular and widely used in large enterprise systems.  
• C#, widely used for its integration with the Microsoft ecosystem.

As with the frontend, the backend also often relies on frameworks—for example Express for NodeJS—but also on other tools, such as cloud services to host applications on remote servers, and containers, to package the application with all its dependencies so it can run on any system.

How data is managed: data storage  

Data storage is any system where data is stored. It is the memory of the application, ensuring the persistence of information and access to it.

The most common are:  

• Database: stores structured data, possibly related to each other. It has its own internal logic, where data is organized and interpreted, and queries can be used to retrieve the desired information.  
• Bucket: stores entire files without applying any logic. It is therefore commonly used to store images, videos, or to perform backups.

These two types of storage sometimes work together. Example: a user uploads their profile image, which is stored in a bucket; in the database, within the user’s profile, the URL where that image is accessible is stored instead.

The responsibilities of data storage services are not limited to preserving data, but also include:  

• Preventing data inconsistencies, for example ensuring a user ID is not missing or incorrectly formatted.  
• Providing data to the backend as quickly as possible.  
• Managing concurrency, meaning when two or more requests attempt to modify the same data at the same time.

How a database works  

At the core of a database is a system managed by a Database Management System, which is responsible for storing data on disk, executing queries, and optimizing performance. Examples include:  

• MySQL  
• PostgreSQL  
• MongoDB
• SQLite
• MariaDB

Data within a database can be organized in different ways. In general, two categories are distinguished based on how data is structured:

• Relational databases organize data into tables, rows, and columns. Tables can also be related to each other.  
• NoSQL databases, on the other hand, do not organize data into rigid tables, but use flexible structures, such as JSON-like documents or key-value pairs.

For an application to work, all the parts we have discussed must cooperate in harmony. And this only concerns the programming side of the application, without taking into account all the other equally important aspects, such as business logic, marketing, SEO, and design.

If you have an idea to develop a web platform and are looking for qualified partners to help you turn it into a real product, get in touch with us at Mabiloft. We will be happy to discuss your idea and help you make it work.