Difference between launch image and splash screen

Question

I was going through iOS Human Interface Guidelines.

It was mentioned as

1. Display a launch image that closely resembles the first sc

Answer 1

The launch image is designed to make the perceived launch time of you app feel faster by showing something resembling the interface that will be loaded as quickly as possible. Displaying a logo does nothing but draw attention to how quickly your app loads and adds nothing to the user’s experience.

If your bundle have default.png then apps takes as a launch image and it remains on screen for 3 seconds