The digital television transition (also called the digital switchover (DSO), the analog switch-off (ASO), the digital migration, or the analog shutdown) is when analog television signals are turned off so digital terrestrial television (DTT) can be used instead. This is done because it gives a better picture quality for viewers, lets more channels be broadcast in one area, and is cheaper to run. In some places, digital cable, satellite, or internet protocol television replaced analog television instead of DTT.