The point size of the type is the distance between the baseline and the height of the ascenders. The x-height, is the height of the body of the characters, or the height of the lower-case x.
An ascender is the stroke above the x-height, or the up-strokes of d's, h's, ect.
A descender is the stroke below the base line, or the tails of the g's and y's. .
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