Similaritis:
Both orbits make the satellite stationary relative to a longitude of the Earth. That means that the satellite would hover ovr the same latitude in both geostationary and geosynchronous orbit.
Both orbits entail that a satellite has a period of roughly the length of a sidereal day, or one rotation of the Earth.
Differences:
Geostationary orbits need to be on the same plane as the equator, while geosynchronous orbits can range in latitude, so the satellitemay appear to shift north and south on the same latitude.
Geostationary orbits are just geosynchronous orbits that are coplanar with the equator.