If you photograph a scene with a light source such as a candle or a light bulb in it you wouldn’t expect, nor want, to be able to see the detail of the candle flame or the bulb’s element.
You would expect these areas to be burned out. Similarly, if you are photographing a sparkling sea you expect the specular highlights to be burned out.
It would be a problem, however, if all the detail in the ‘white horses’ of the waves in the sea are a featureless mass of overexposed white.
These areas are the important highlights or critical highlights and the exposure needs to be set to protect them.