What's the Difference Between a Spy Balloon and a Satellite?

The timing is the most interesting thing of all of this to me, especially after the Pentagon said over the weekend that there had been several other balloons. It's maybe important to note that the US says that they knew about the balloon when it was in Alaska. By the time it reached Montana, people on the ground knew that there might be a spy balloon. The value of the intelligence collected may be different if you know that somebody is watching and behaviors can be changed.