A reaction essay is an essay that is written in response to something else. The initial topic that the writer is responding to could be anything from a speech that was heard to another essay to the latest breaking news event.
We've all heard the cliche, good things come to those who wait. And in some ways it rings true. We are born into a world in which we wait for a lot of things and how we spend our time waiting is often the determinant of whether we are successful or not in whatever the endeavor may be.