Launch Modes in Android
Launch modes are classfied in to
Standard : if we didnt mention any launch mode for the activity then it take the default one that when you launch Activity B from Activity A then again Activity A from B mean it wont reuse the existing instances from the stack instead it will create a new instance.
SingleTop : if the recent launched activity is present at the top mean it will resuse that activity instead of creating a new instance by invoking onNewIntent() method.
SingleTask : it will create a new stack from their it build the next activities on that new stack
singleInstance : it is similar to singleTask but one difference is that there will be only one activity will present in a stack it wont allow other activity.