What is an interface? Explained in simple terms

Interface is a concept found in both design and information technology. However, each field has its own specific characteristics. In design, interface typically refers to the visual elements with which the user interacts, including buttons, menus, and other components that provide a convenient and intuitive experience. In IT, interface can refer to both the user interface (UI) and the application programming interface (API), which serve to interact between various software components or systems. Thus, despite the general essence of the term, its meaning varies depending on the context.

An interface is the way a user interacts with software or a device. UX/UI expert Evgeny Knyazev and web developer Mikhail Malyshev explain in simple terms that an interface includes all the elements with which the user can interact, such as buttons, menus, and other graphical components. A good interface ensures ease of use and intuitive perception, which contributes to a better user experience. Proper interface design plays a key role in the success of any digital product.

CEO of Antro, art director and product designer with extensive experience. Speaker at such events as Product Sense and ECOM Expo. Author of the educational course "Logomachines" dedicated to the development of mobile interfaces. He is also a jury member of the Russian Drupal Awards, which underlines his expertise in the field of web design and development.

What is an interface?

The word "interface" in English brings to mind interaction and face. These elements emphasize the essence of the term - the interface serves as a link between the user and the system. However, when studying definitions in sources such as Wikipedia, one may encounter unclear wording. It is important to understand that an interface is not just a set of elements, but a complex tool that ensures the convenience and effectiveness of interaction between people and technology. A proper understanding of the interface helps to create more intuitive and accessible solutions, which is especially relevant in today's digital world.

An interface is a tool that facilitates interaction between two systems or objects. It is a key element that allows different programs, devices, or users to exchange information and collaborate effectively. Understanding and using interfaces correctly greatly simplifies processes and improves user experience.

Imagine you've decided to drink a Coca-Cola from a river filled with the drink. You'll probably try to interact with it with your hands. Your hands serve as the interface through which your nervous system interacts with the outside world. In fact, it's your brain that wants to perform a certain action but can't directly act on objects. Therefore, it uses available tools, such as your body, and your hands are an important part of it. Thus, interaction with the external environment occurs through physical actions, which emphasizes the importance of our body as an interface in everyday life.

An interface is a system of interfaces

In theory, you could pour Coca-Cola into your palms and drink it. However, this is an inefficient way to use the drink. This approach leads to spills, resulting in your hands becoming sticky and wet, which is uncomfortable. Moreover, it is impractical and impractical from a convenience standpoint. Proper choice of packaging and consumption method significantly improves the experience.

The mug is an interface that enables human interaction with beverages like Coke and others. This interaction can be viewed as part of a larger system that can be decomposed for better understanding. Every detail, from the mug's shape and material to its ease of use, affects the overall beverage consumption experience. Thus, the mug is not just a vessel, but an important element that shapes our perception and interaction with liquids.

The brain wants a drink.
It uses its hands for this. But hands alone are a lousy interface for Coke, so...
It figures out how to do something with its hands depending on the context and environment in which it finds itself. For example, he makes a mug from some leaves and branches or buys a ceramic one at the store.
And then his hands take the mug—the result is a pretty good interface: the Coca-Cola doesn't spill, and the brain enjoys the sugar.

Different contexts require different interfaces

The mug can be with or without a handle. There is also a tumbler option with a cup holder, which provides a convenient handle for this smooth glass. The choice of shape and design of the mug depends on personal preference and functionality.

The choice of a mug for a drink can vary depending on its type. Coca-Cola can be drunk from any container, even from an espresso cup. Although this may seem unusual, no one will criticize this approach, and the taste of the drink will not change significantly.

Drinking wine from an espresso mug can be confusing for true wine connoisseurs. Wine lovers have specific requirements for glassware, which not only serves as a serving vessel but also helps enhance the aroma and flavor of the drink. Choosing the right wine container is essential, as it must meet aesthetic standards and ensure the full perception of all organoleptic characteristics. Using specialized glasses allows you to enjoy the exquisite bouquet and texture of wine, which makes the tasting process more enjoyable and memorable.

The lawyer's mug from the TV series "Breaking Bad" and "Better Call Saul" is not only an interface for drinking, but also for communication. Every client from the Albuquerque underworld can read the phrase "World's Greatest Lawyer" on it and be filled with respect (if they can read English, of course). Still: TV series "Better Call Saul" / Sony Pictures Television

What interfaces do designers work on?

In the context of product design, an interface is the visible part of a web service or mobile application, including browsers, games, and online stores. The primary function of an interface is to enable user interaction with the system by effectively conveying the necessary information. Proper interface design plays a key role in creating a positive user experience, which in turn affects the success of the product. A well-designed interface not only simplifies navigation but also promotes a deeper understanding of the app's functionality, making it more appealing to users.

The interface of an Asian e-commerce platform. And it’s not very goodScreenshot: Lazada / Skillbox Media website

The interface of the same retail service’s appScreenshot: Lazada / Skillbox Media app

From a design point of view, there is a noticeable difference between the web and mobile interfaces, although ultimately they both represent a Figma layout. Web interfaces typically require a more complex structure and thoughtful navigation, while mobile interfaces emphasize simplicity and ease of use. Given the specifics of each format, it is important to adapt the design to specific devices to ensure maximum functionality and comfort for users.

An example of a Figma layout. This is a mobile app interface. Screenshot: Daria K. / Figma / Skillbox Media

The work of an interface designer is significantly different from creating graphic or motion design. In product design, the focus is not only on the attractive aesthetics of forms, colors, fonts, and compositions. While visual elements (UI) play an important role and influence user perception, interface design goes beyond just visual design. The key aspect is creating a functional and intuitive interaction that provides convenience and enhances the user experience.

Separating the concepts of UI and UX is a complex task. Firstly, there is no consensus on this issue among designers. Secondly, in our company, there is a clear understanding: UI is an integral part of UX. The user interface (UI) is inherently linked to the user experience (UX), and we believe that separating these two elements is incorrect. The correct interaction between the interface and the user experience is crucial for creating effective and user-friendly products.

The term "design" in English is translated as "designing." Thus, interface design is the process of designing usable and functional solutions, and not just the creation of visual elements. The main goal of interface design is to provide users with an intuitive and comfortable experience interacting with the product. This includes not only aesthetic aspects, but also ergonomics, accessibility, and user navigation. It is important to remember that good interface design contributes to increased user satisfaction and the effectiveness of working with an application or website.

An interface designer must consider not only the visual appeal of their work, but also usability—an aspect known as user experience (UX). Such a designer is obliged to look beyond appearance alone, understanding how the user will interact with the interface. In his work, not only static elements are important, but also animations, the design of smooth transitions and system reactions to user actions. Careful attention to these aspects allows you to create more intuitive and pleasant to use interfaces.

This set of buttons, text, images, transitions, and animations allows the user to effectively interact with the device system, allowing them to achieve the desired results. Correct use of these interface elements contributes to an improved user experience and increases the functionality of the application.

Creating an effective interface requires a deep understanding of the principles that allow the user to comfortably interact with the product. Knowledge of Nielsen's ten heuristics is a key aspect in this process. These principles will help you avoid common mistakes and create an intuitive design that promotes a better user experience and increased customer satisfaction. Correct application of these heuristics will not only improve the functionality of the interface but also significantly increase its appeal to users.

Web developer with experience in such companies as Rocketbank and Yandex. Currently holds the position of Frontend Tech Lead at Timestripe and is a Fullstack TypeScript Developer at Playdex. Also runs a Telegram channel dedicated to the frontend and web 3.0. My experience covers a wide range of technologies and tools, which allows me to effectively create modern web applications.

What is an interface in programming?

An interface is a convention that governs the exchange of information between the components of a computer system. It defines the rules and formats of interaction, ensuring compatibility and effective communication between different elements. A proper understanding of the interface is important for software development and systems integration, as it serves as the basis for interaction between various modules and devices. An effective interface simplifies the data exchange process and improves the performance of the system as a whole.

Exchange can occur between software, computer components, peripherals and other hardware, as well as between the user and the computer. It is important to understand that effective data exchange plays a key role in ensuring compatibility and performance of the system. Such exchange may include the transfer of information, commands, or resources, which significantly simplifies interaction between various elements of the IT infrastructure.

Let's consider examples of interfaces, ranging from high-level to low-level. Abstraction levels play an important role in software development: the lower the level, the deeper we dive into implementation details, which requires a more detailed description of the program. For example, zero-code programming is at a higher level of abstraction compared to traditional programming, since when writing code, developers must explicitly specify every implementation detail. This highlights the differences in approaches to creating software solutions and the importance of choosing the appropriate level of abstraction depending on the goals of the project.

What types of interfaces are there?

Let's consider the three main types of interfaces with which users and developers actively interact. Each of these interfaces plays a key role in ensuring the convenience and efficiency of working with software. Understanding these types will help better tailor systems to user needs and improve the overall user experience.

Hardware interfaces are essential for communication between physical devices. They allow different devices to exchange data and interact with each other, a key aspect in modern computer systems and electronics. Proper selection and use of hardware interfaces ensures the efficiency and stability of all equipment.

A MIDI keyboard's interface plays a vital role in its functionality and usability. Typically, such devices are equipped with standard MIDI outputs, allowing them to be connected to computers, synthesizers, and other musical instruments. Many models offer USB connectivity, simplifying integration with modern digital audio workstations and music production software. Additionally, some keyboards feature additional controls, such as faders, buttons, and rotary knobs, which provide more flexible control over audio parameters. When choosing a MIDI keyboard, it's important to consider how well the interface suits your needs and working style.

It's compatible with both MIDI and USB, which provides greater flexibility.

Wired interfaces include USB and Thunderbolt, which provide high data transfer rates and a reliable connection. Wireless technologies, such as WiFi and Bluetooth, offer convenience and mobility, allowing you to connect devices wirelessly. These interfaces play a key role in modern equipment, ensuring compatibility and functionality across various gadgets.

API stands for Application Programming Interface. An API is a set of rules and protocols that allow various software applications to interact with each other. It facilitates integration between systems, enabling the exchange of data and functionality. The use of APIs is becoming increasingly popular in software development because they enable developers to create more complex and efficient applications and simplify the process of interacting with external services and resources.

Application programming interfaces (APIs) are used to integrate various software solutions. They allow applications to exchange data and functionality. For example, a mobile application can access data on a server by sending requests to the server's API. This ensures efficient interaction between systems and simplifies the software development process.

APIs are strictly regulated and can vary significantly depending on the specific application. This is why API developers create detailed documentation that describes how other developers should integrate with this API. Proper understanding and use of documentation allows for effective interaction with the API and optimizes development processes.

APIs, or application programming interfaces, are an important tool for developers. They are often referred to as "api". APIs allow various software systems to interact with each other, providing the exchange of data and functionality. This simplifies application development, as developers can use ready-made solutions and integrate them into their products. Understanding the role of APIs in modern programming is important, as they contribute to the creation of more flexible and scalable applications.

An endpoint is one of the available methods in an API that allows you to interact with specific functionality. For example, the Spotify API has an endpoint for adding a song to a playlist. This method allows developers to integrate music content and manage playlists on the platform. Endpoints play a key role in APIs because they allow for efficient querying and data retrieval, making them indispensable tools for developers working with various services.

At Yandex, an endpoint is often called a handle. This term is used to refer to an interface that allows you to interact with various services and access data. The handle plays a key role in the development and integration of applications, ensuring efficient interaction between systems.

In object-oriented programming

An interface in object-oriented programming is a definition of the structure of an object that does not contain the details of its implementation. It specifies a set of methods and properties that a class must implement, thereby providing a standard for interaction between the various components of the system. Using interfaces allows you to increase the flexibility and scalability of your code, making it easier to maintain and test. It is important to note that interfaces facilitate the implementation of the principles of encapsulation and polymorphism, making them a key element in the development of modern software solutions.

An example in Java — made specifically for this article. Image: from the personal archive of Mikhail Malyshev.