A TV tuner allows a person to receive signals on his or her television, and therefore receive different channels. It converts signals into pictures and sounds. The oldest type of tuner was simply the dial used to change channels and allow the television to pick up different analog signals broadcast over the air. Sometimes, in order to get certain cable channels, a TV needs a special box purchased or rented from a cable company.
A basic tuner is available in most TVs, or through most cable companies. Televisions sold in the US as of mid-2007 were required to include a digital tuner to allow the set to pick up digital television signals by antenna. In addition, many people have a TV tuner card, or exterior tuner that allows them to receive television programming on a computer screen. Essentially, this can convert a computer to a television, and depending on the owner's cable service, it may allow him or her to watch a wide number of television stations.
Many people use tuner cards to watch free, over the air television on their computers without using a cable service. To receive digital television broadcast signals with this card, the user will usually need to attach an antenna.
Care is required when purchasing a card or an exterior TV tuner, since not all tuners work with all computer systems. Some are specifically designed for Macs or PCs, and many require additional software in order to view images. They may also require a certain amount of memory to work correctly.
Some argue that it's a waste of money to set up a computer to show television programming, especially at a computer desk. If families, for instance, enjoy watching TV together, it may be somewhat uncomfortable to arrange a whole family around a desk to watch a small screen. As technology advances, however, it is possible to buy a large computer monitor that can be used in place of a television, or to attach a laptop or other computer to a TV and use it as the display.
Watching TV through a computer seems a popular trend that is likely to continue. Especially with increasing numbers of laptops, a TV tuner may be a great purchase for people who live alone, for people who are on the road frequently, or for kids living in dorms. Since headphones are relatively inexpensive, a person watching TV on a laptop is not likely to annoy his or her roommates.
Some tuners will also pick up FM radio signals, so they can provide a way to listen to radio stations as well. Many TV tuners are far more expensive than a simple radio, however.