difference between interface and abstract class
Interfaces specify what a class must do. It is the blueprint of the class. It is used to achieve total abstraction. We are using implements keyword for interface. Basic statement we all know in Selenium is WebDriver driver = new FirefoxDriver(); WebDriver itself is an Interface. So we are initializing Firefox browser using Selenium WebDriver. It means we are creating a reference variable of the interface and creating an Object. So WebDriver is an Interface and FirefoxDriver is a class. Sometimes we may come across a situation where we cannot provide implementation to all the methods in a class. We want to leave the implementation to a class that extends it. In that case we declare a class as abstract by using abstract keyword on method signature.In my framework I have created my PageBase class as super class of the all page classes. I have collected all common elements and functions into PageBase class and all other page classes extent PageBase class. By doing so, I don't have to locate very common WebElements and it provides reusability in my framework. Also 1)Abstract classes cannot be instantiated 2)An abstarct classes contains abstract method, concrete methods or both. 3)Any class which extends abstarct class must override all methods of abstract class 4)An abstarct class can contain either 0 or more abstract method.