@miriam98 - Yes, I agree. You should definitely consider all the equipment you need before you make a purchase. Depending on your situation, you don’t necessarily need the satellite or cable box. It depends on what kind of transmission you’re receiving and what kind of television you have.
If you’re just getting regular TV stations over the air using the traditional “rabbit ears” and you still have an analog TV, then all you need is a digital TV converter. This converter will sit on top of your television and then convert the digital over the air signals to analog so that you can view them on your analog set.
I realize that most people have digital televisions nowadays, but some people still have analog sets. In this case the converter box and the SDTV tuner would be all that they need.