# What is Interface?

*Development · Last updated: October 12, 2026*

It is a common communication boundary that allows a user to manage a system or two software components to communicate with each other.

## Overview

An interface refers to the meeting point where two independent systems or a human and a computer interact. In the software world, it is an umbrella term that defines all types of contact surfaces, from graphical screens (UI) to data bridges between systems (API). In object-oriented programming, it serves as a binding technical contract that declares which functions a component will offer to the outside world.

***Analogy:** A car's steering wheel and pedals are the interface that allows the driver to manage the engine; the standard sockets where the engine cables under the hood connect to each other are the interfaces of the parts themselves.*

## How it works

The complex mechanism in the background of the system is hidden, and standard control paths accessible to the outside world are defined. While this interaction is presented to humans through buttons and forms, for software, it is carried out through code functions bound by specific rules. Even if the internal structure or code is completely renewed, as long as the interface rules are maintained, the connection continues to work without breaking.

## Where it is used

It is used in website navigation menus, mobile application screens, operating system command lines, and background services where servers share data with each other.

## Commonly confused with

It is often confused with the user interface (UI), which is only screen design. However, UI is only the human-facing part of the interface; APIs where machines talk to each other are also interfaces.

## Questions and answers

**Are interface and UI the same thing?**

No: UI covers the screens that a human directly sees and touches, while the general interface is a broader term that also includes the invisible contact points where software communicates with each other at the code level.

**Why is an interface important in software development?**

It ensures that code written by different teams can be integrated seamlessly based only on established rules, without needing to know each other's internal details.

## Related terms

- [User Interface](https://trescout.com/en/dictionary/user-interface/)
- [API](https://trescout.com/en/dictionary/api/)
- [GUI](https://trescout.com/en/dictionary/gui/)
- [Web Interface](https://trescout.com/en/dictionary/web-interface/)
- [CLI](https://trescout.com/en/dictionary/cli/)

## Related tools

- [Flutter](https://trescout.com/en/discover/flutter/)
- [Open Webui](https://trescout.com/en/discover/open-webui/)
- [Imgui](https://trescout.com/en/discover/imgui/)
- [Page Agent](https://trescout.com/en/discover/page-agent/)
- [Tuicr](https://trescout.com/en/discover/tuicr/)

This explanation was written in plain language for TreScout with AI and **machine-translated** from the Turkish original · the Turkish version prevails. If something looks wrong or missing, write to [hello@trescout.com](mailto:hello@trescout.com). [Read in Turkish →](https://trescout.com/dictionary/interface/)

---
Source: TreScout Dictionary · https://trescout.com/en/dictionary/interface/