"The poof" is named, as one of the main ways Quinn says. It is one of the names as "The big blink" "The jump" and there are many other ways.
In GONE, it doesn't describe much about it, Emma and Anna blink out, but it doesn't say anything until the middle of the book. When it does explain it, it describes a lie, your parents or your mother trying to convicne you to come over to the other side, however to viewers, it is just a green monster.
In FEAR, it describes where everybody who disappeared at the first second had appeared. It is also said that if you "jump out," you will suffer server damage, as Francis and Mary die in FEAR.