A hybrid app is a type of mobile application that combines elements of both native and web applications. It is built using web technologies like HTML, CSS, and JavaScript, and is wrapped in a native container, allowing it to be installed on devices like a native app. This approach enables developers to create a single app that can run on multiple platforms, such as iOS and Android, reducing development time and costs. Hybrid apps can access device features, such as the camera and GPS, through plugins, making them versatile. They are often faster to develop and easier to maintain than fully native apps, but may not perform as well in terms of speed and responsiveness.