1-> main or Activity 2-> Services 3-> Broadcast receiver 4-> Content Providers
/*
-> if we want to access any function or any member variable of class then we have to create an object of that class and then we can access through that object -> How can we access without crating an object
By the use of static keyword its possible Ex - public static String name ="Nalini";
As written below we have to crate an companion object in this companion we can declare the variable or function But if you want to access this variable in a java class then you have to use an annotation @JvmStatic companion object { @JvmStatic val TAG: String = "TAG" }
const val -> This the keyword use to declare a immutable variable at compile time compile time -> compile time meaning at the time of building
*/