HOMONYMS are words that sound alike but have different meanings.Homophones are a type of homonym that also sound alike and have different meanings, but have different spellings.
Homophones:
to/two/too
there/their/they're
pray/prey
HOMOGRAPHS are words that are spelled the same but have different meanings.Heteronyms are a type of homograph that are also spelled the same and have different meanings, but sound different.
Homographs:
lead (to go in front of)/lead (a metal)
wind (to follow a course that is not straight)/wind (a gust of air)
bass (low, deep sound)/bass (a type of fish)
WORDS THAT BOTH SOUND THE SAME AND ARE SPELLED THE SAME are both homonyms (same sound) and homographs (same spelling). Example: lie (untruth) and lie (prone); fair (county fair), fair (reasonable).
http://languagelearningbase.com/88967/homonyms-homophones-homographs-commonly-confused-words