Airdam or Splitter?

[Nigel]

Just been looking at production cars, and the performance variants seem to have airdams with a horizontal section facing forwards.
Two quick questions - Is that what is known as a splitter, rather than an airdam.
And, as they are designed to provide some downforce (I believe) do they have more drag than a simpler airdam?

[ncs]

Some reading

APR Performance - Splitters

For splitter, a general guideline is 2x longer than the ground clearance to be effective. So if the bumper is 2 inches off the ground, the splitter needs to stick out 4 inches. They are kind of dangerous, and possibly illegal on street cars.

[tasdrouille]

Splitters usually have little effect on drag. In most instances they can reduce lift, but not much on passenger gars, and helps cram more air through the rad.