Over- and Underexposure due to strong Contrast
The second principle needed to understand exposure metering is:
Digital cameras can render a smaller range of contrasts in brightness than the human eye.
Please see the following example: Two photos of the same subject with very strong contrasts, taken with different exposure.
The difference in brightness between the tree in the shadow and the cloud lit by the sun is so huge that that when exposing long enough to get the tree bright enough the cloud gets completely overexposed and unrecognizable. Vice versa a darker exposure that shows all details of the cloud leads to a foreground that is way too dark.
The pictures are taken with a compact camera; other cameras with a larger sensor can deal better with such contrasts in brightness but the basic problem does not disappear.
This means: If your subject has really strong contrasts there is no „right“ exposure that renders all parts of your image well.
The camera electronics or you as a photographer that intervenes in the exposure have to decide which parts of the image you sacrifice as over- or under exposed.