Answer :
It means that the satellite's orbital period is equal to the Earth's rotation period ... roughly 23 hours 56 minutes 4 seconds ... so that the satellite always stays over the same longitude.
IF that satellite's orbit has also been carefully placed over the equator, THEN the satellite is in a 'geostationary' orbit. It appears motionless in the sky, and can be used to sell 900 channels of TV to people with little dishes that they never need to move.
IF that satellite's orbit has also been carefully placed over the equator, THEN the satellite is in a 'geostationary' orbit. It appears motionless in the sky, and can be used to sell 900 channels of TV to people with little dishes that they never need to move.
