To watch TV, we need a satellite dish and a receiver. These two components are what allow us to receive and transform the signals that contain TV programs which are emitted by satellites and broadcast centers.The dishThe satellite dish captures the signal that reaches the viewer's house. Think of the dish as a special kind of antenna that focuses on a specific broadcast source. The standard dish that is widely used nowadays has a parabolic shape and a central horn. This horn plays the role of the transmitter while the dish focuses the signal into a narrow beam.The dish plays the role of the receiver – it can't transmit signals. It works the opposite way of the horn. The dish reflects the incoming radio signal inward onto a particular point, like a concave mirror.Sometimes we need to receive signals from more than just one satellite. It's possible using a single horn dish – the quality, however, is compromised because the dish isn't focused on one particular source of signal.This problem can be solved with new dish designs. These modern dishes use more than one horn to receive radio signals from multiple satellites without compromising the quality. When the dish receives two signals at the same time, these two signals are reflected at different angles, which leads to one signal hitting one of the horns and the other signal hitting the other horn.The receiverThe receiver is the last component in the TV system. It has 4 major roles:It decompresses the signal. Because all broadcast signals are compressed, the receiver needs to decompress them to actually be able to read them. To decompress the signal, the receiver needs a proper decoder chip for that programming package. This chip can be communicated to the receiver via satellite signals so that it could decode the encrypted programs.To counter illegal use, the provider might send signals that disrupt illegal decompressors as a counter measure.The second role of the receiver is to convert the digital signal into an analogic signal that a standard television can read. In the US, signals are converted from digital to analog National Television Systems Committee (NTSC) format. Some TV setups can also output HDTV signal.The receiver also sorts different signals from the larger satellite signal and sends just the signal you need. For example, if you switch between channels, the receiver switches to another signal for that channel. Since the receiver only displays one signal at a time, it's impossible to watch two channels at the same time, or record a channel while watching another one.It monitors pay-per-view programs and contacts the provider to communicate billing information.Receivers have many other features like a digital video recorder which allows you to record a specific TV program at a certain time to watch later, and an internal hard drive to save what you recorded like movies and TV shows. The latter have a big memory size, so you need a hard drive of at least 500GB.