Well, actually it’s more than that. Stealth is trying to make the plane less observable to the defense .in as many aspects of detection as possible. So it can get in and do its main work.
Low observable technologies refer to the way the attacker prevents the defense force from detecting the aircraft by the technology adapted to it.
Lets look at an F-117 for the examples of low observable technology that make the plane stealthy.
RADAR - the signal that bounces back to the receiver identifies it right? So if you reflect the signal away from the receiver, absorb it, or change its frequency, this mean the receiver doesn’t see the signal and the plane isn’t there.
The F-117 does two of these processes: The angled skin redirects the signal away from the receiver, and RAM coating absorb some of the signal.
Noise: the Soviet Union had one of the largest networks of listening devices in the world to detect the high pitch noise of the engines or exhaust for a planes detection.
The F-117 buried both engines deep in the fuselage, made two small engines instead of one, and fanned the exhaust to break up the sound waves.
Heat: The plane releases heat in the form of the engine, and exhaust, which can be detected on an infra-red optical display.
F-117 defeats this by a high capacity fan attached to the compressor section, which routes cold intake air around the engine casing cooling it down, and mixing with the exhaust before it exits the fan. Pre-cooling the exhaust and breaking it up cools it quicker.
Mark 1 Eyeball: Hell, you can see it.
F-117 is painted black, and works at night. You are very lucky to see it all.. They tried to place lighting on it, to give it a daytime capability, but it failed miserably.
Now they have new ways to detect things...my favorite is like a weather radar...instead it works on the probability that a moving group of nothing might be something worth detecting.