reading vs skimming

reading and skimming both are nouns.

Word	Noun	Adjective	Verb	Adverb
reading	Yes	No	No	No
skimming	Yes	No	No	No

As nouns, skimming is a hyponym of reading; that is, skimming is a word with a more specific, narrower meaning than reading:

reading: the cognitive process of understanding a written linguistic message
skimming: reading or glancing through quickly

Other hyponyms of reading include speed-reading, perusal, perusing, poring over, studying, browse, browsing, skim.

reading (noun)	skimming (noun)
the act of measuring with meters or similar instruments	the act of removing floating material from the surface of a liquid
the cognitive process of understanding a written linguistic message	failure to declare income in order to avoid paying taxes on it
a mental representation of the meaning or significance of something	the act of brushing against while passing
a datum about some physical state that is presented to a user by a meter or similar instrument	reading or glancing through quickly
written material intended to be read
a particular interpretation or performance
a public instance of reciting or repeating (from memory) something prepared in advance