Setting Up a Virtual Device and Running Your App
As a part of installing Android Studio, you downloaded and installed the latest Android SDK components. These included a base emulator, which you will configure to create a virtual device to run Android apps on. The benefit is that you can make changes and quickly see them on your desktop whilst developing your app. Although virtual devices do not have all the features of a real device, the feedback cycle is often quicker than going through the steps of connecting a real device.
Also, although you should ensure your app runs as expected on different devices, you can standardize it by targeting a specific device by downloading an emulator skin even if you don't have the real device if this is a requirement of your project.
The screen you will have seen (or something similar) when installing Android Studio is as follows:
Let's take a look at the SDK components that are...