I have heard many singers use this technique, but I have no idea what it is called, and so I cannot find any information about it on the web. I will do my best to describe it.
When a singer switches to falsetto in the middle of singing a note without stopping. The result is a small sort of "break" in the voice and then the singer is singing a higher note in falsetto. I also think that I've heard the opposite, when a singer switches from falsetto to a regular voice while without stopping.
Here is an video with example of this: the singer does this at 3:10.
What is it called, and where can I find videos that teach about it?