What is a Chrome custom tab?
Well, most of us know tabs from every day Internet browsing. It doesn't really matter which browser you use; all browsers support tabs and multiple tabs' browsing. This allows us to have more than one website open at the same time and navigate between the opened instances. In Android, things are much the same, but when using WebView, you don't have tabs.
What is WebView?
WebView is the part in the Android OS that's responsible for rendering web pages in most Android apps. If you see web content in an Android app, chances are you're looking at WebView. The major exceptions to this rule are some of the Android browsers, such as Chrome, Firefox, and so on.
In Android 4.3 and lower, WebView uses code based on Apple's Webkit. In Android 4.4 and higher, WebView is based on the Chromium project, which is the open source base of Google Chrome. In Android 5.0, WebView was decoupled into a separate app that allowed timely updates through Google Play without requiring firmware...
