* Satellites generally orbit within the thermosphere. This is the layer of Earth's atmosphere above the mesosphere and below the exosphere.

* The exosphere is the outermost layer of Earth's atmosphere. It's extremely thin and gradually fades into outer space.

* While the exosphere is technically part of Earth's atmosphere, it's not a practical place for most satellites to orbit. The exosphere is so thin that it doesn't provide much atmospheric drag to slow down satellites. This means satellites would need a lot of fuel to maintain their orbits. Additionally, the exosphere is far from Earth, making communication and data transmission much more difficult.

Here's a simplified analogy:

Think of the exosphere like the very edge of a very large pond. It's still part of the pond, but it's mostly empty and doesn't have much water in it. Satellites are like boats that need water to stay afloat. They're better off in the denser water of the pond, which is like the thermosphere.

In short: While technically the exosphere is part of Earth's atmosphere, most satellites orbit within the thermosphere, a layer much closer to Earth where there's more atmospheric drag and better communication possibilities.