This jinx is used to prevent disapparation and is used to entrap an enemy in an area.

Albus Dumbledore used this jinx in the "Department of Mysteries" in "Harry Potter and the Order of the Phoenix" to keep the Death Eaters from going away.
This jinx is maybe also used in Hogwarts because it's always mentioned that no one can disapparate in this school.

Hello, my witches, wizards and muggles, that was the chapter for today!
I hope you liked it and we'll read us again next week!