web log vs microblog

web log and microblog both are nouns.

Word	Noun	Adjective	Verb	Adverb
web log	Yes	No	No	No
microblog	Yes	No	No	No

As nouns, microblog is a hyponym of web log; that is, microblog is a word with a more specific, narrower meaning than web log:

web log: a shared on-line journal where people can post diary entries about their personal experiences and hobbies
microblog: a blog in which there is a limitation on the length of individual postings.

web log (noun)	microblog (noun)
a shared on-line journal where people can post diary entries about their personal experiences and hobbies	a blog in which there is a limitation on the length of individual postings.