One key difference is the orbit of the satellites.
Traditional satellite Internet uses a constellation of 10's of satellites in geostationary orbit (35,000 km elevation) - since they are so far away relatively few satellites are needed but latency and bandwidth are pretty bad.
Next gen satellite Internet like starlink and kuiper use constellations of 1000's of satellites in low earth orbit (550km elevation). These are super close so latency is much better, but you need way more satellites to get consistent coverage- but that also means bandwidth can be much better too.
These low earth orbit satellites are so close that they can basically put standard cellular antenna on them and they act like cell towers in space. Your phone can use the same antenna it already has to connect to them. But the signal is pretty weak so to start they will only support text messaging. Still, that's good enough to replace things like my Garmin InReach so I'm pretty excited.
At least that's my understanding from the T-Mobile and starlink partnership- this Samsung thing might be something slightly different.