How Android App open websites inside the app?

In Android application, we have a component name as WebView. WebView is used to open any url inside our application.

While developing android application, we can create one page that is having WebView component with width and height as of our device. Now whenever we want to open any url in our application we can just open that WebView page and open a particular url in that WebView.

Note : Mobile Browsers work on the same concept.