Streaming TV shows and movies directly to your home is a breeze with Netflix. As a Netflix member, you can instantly watch TV and movies on your PC, Mac, mobile device, or television. Get a free thirty day trial membership. Go to Netflix dot com, slash stuff and sign up today. Welcome to brain Stuff from how Stuff works dot com where smart Happens. I am Marshall Brain with today's question, what does a V chip really do and how does it work? As of all new television sets sold in
the United States have to contain a V chip. The V stands for viewer control and the goal of the chip is to allow parents to choose the level of TV programming that will be allowed into the home. The idea behind a V chip is simple. TV shows have a signal embedded into them that gives the show a rating, and the chip can detect these ratings. The ratings that the FCC has settled on look like this. T v Y is for all children. All children can watch because
it has zero violence and zero sexual content. TV Y seven for all children seven and over. Tv G is for general audiences. There's no sex, violence, or inappropriate language. Tv PG is parental guidance suggested TV fourteen is suitable only for people over fourteen, there's some sex and violence, and then t V M A is suitable only for mature audiences and it can contain just about anything. A parent can program the TV with a rating, and the
TV will block all shows above that rating. So if apparent programs in the TV Y seven rating, the TV will allow only shows rated at t V y or t V Y seven, but it will block all other shows. How does your TV see the rating of a show? The ratings are encoded in what's called the line twenty one data area. All sorts of things go inside this data area, such as closed captioning information and the time
of day, as well as the ratings information. It's basically hidden in a part of the TV signal that doesn't show up on the screen. The V chip simply decodes the line twenty one data, compares it with the parents allowed rating that they've programmed into the chip, and then
either blocks the signal or lets it through. For more on this and thousands of other topics, does it How staff works dot com Audible dot Com is the leading provider of downloadable digital audio books and spoken word entertainment. Audible has over one hundred thousand titles to choose from to be downloaded to your iPod or MP three player. Go to audible podcast dot com slash brain stuff to get a free audio book download of your choice when you sign up today