A satellite is something that goes around and around a larger something, like the earth or another planet.
Some satellites are natural, like the moon, which is a natural satellite of the earth.
Other satellites are made by scientists and technologists to go around the earth and do certain jobs. Some satellites send and receive television signals. The signal is sent from a station on the earth's surface. The satellite receives the signal and rebroadcasts it to other places on the earth. With the right number of satellites in space, one television program can be seen all over the world.