[rob74]

To muddle things even further, there is a (jet) aircraft manufacturer called Gulfstream (https://en.wikipedia.org/wiki/Gulfstream_Aerospace).

...but I fully agree with the rest of your comment.

[buildsjets]

Not all Gulfstream aircraft are jets. Mine certainly isn’t. Piston powered, burns avgas, spins a propeller, goes around 130 knots.