Scrcpy is an open-source application that allows users to display and control their Android devices connected over USB or TCP/IP. It does not require root access or an app installed on the device and works on Linux, Windows, and macOS. The application provides features such as audio forwarding, recording, virtual display, and mirroring with Android device screen off. It also supports gamepad control and can be used to install APKs that are unavailable for the device via the Play Store.