What is Speedwork?

MishMash95 Posts: 104
So I keep seeing the term "speedwork" chucked around on the web. Though lots of people seem to claim it means different things. I've heard it used to refer to anything from high intensity intervals, improving aero position, sprints, sprints into threshold, and even used to decsribe high-cadence drills used during a recovery week.

Is there a general rule of thumb for this type of workout? That is, when people say its good to mix in "speedwork" what are they specifically talking about? Is it just the obvious high intensity/high speed race-style interval that the name would suggest?