Unity is a game engine from Unity Technologies. A game engine is software that provides rendering, physics, sound, input and scripting, so that a team builds a game on top of it instead of writing those systems itself. Unity builds 2D and 3D games and interactive applications and deploys them to more than 25 platforms, from mobile and PC to game consoles and XR (extended reality: virtual and augmented reality).
Work happens in the Unity Editor. A new project opens with a sample scene that contains a camera and a light, and the developer adds assets, animated characters and sound. Scripts are written in C# on .NET, with tools such as Visual Studio or JetBrains Rider. Unity also offers multiplayer tools, collaboration and version control, the Asset Store for ready-made assets, and services that acquire players and earn money from ads and in-app purchases. Outside games, it is used for 3D collaboration, training, robotics and automotive interfaces.
Unity is sold as subscription plans. Unity Personal is free for individuals and small businesses under a revenue and funding limit; Unity Pro, Enterprise and Industry are paid.