Both methods return an empty list, but Collections.emptyList() returns a list that is immutable. This mean you cannot add new elements to the "empty" list. At the background, each call of Collections.emptyList() actually won't create a new instance of an empty list. Instead, it will reuse the existing empty instance. If you are familiar Singleton in the design pattern, you should know what I mean. So this will give you better performance if called frequently.
