My concern is the following,

If I create a Class with some method and inherit it then which methods are called `lifecycle` methods.

Are all overridable methods lifecycle methods? And in which category does it fall e.g OOPS ,OOAD 

**Example**:- In iOS `viewDidLoad` is a `lifecycle` method but `didReceiveMemoryWarning` is not.
If it is not called a lifecycle method , is it called a overridable method?