A Virtual Device is a software-based simulation of a physical device, allowing users to run applications or perform tasks without needing the actual hardware. This technology is commonly used in software development and testing, enabling developers to create and test applications in a controlled environment. Virtual devices can mimic various operating systems and hardware configurations, making them versatile tools for developers. They are often used in conjunction with platforms like Android Studio or VMware, which provide the necessary frameworks to create and manage these virtual environments efficiently.