Marvin the Martian wrote:

Again, a sounding rocket is one that simply goes up high in the
atmosphere and doesn't even get close to LEO.

No, that's just what sounding rockets happen to do. It's not what they are. A sounding rocket is a rocket whose payload
takes soundings, i.e. measurements, of its environment. A sounding rocket could go way up to orbital altitudes, taking
measurements of the atmosphere when it gets there, and still be a sounding rocket.