A homophone is a word that sounds the same as another word but has a different meaning usually with a different spelling. like there, their, and they're. there is over there, their means that is their toy, and they're is a contraction for they are.
Example: Do you know where sally and charlie are?
THEY'RE over THERE
Are you here to return THEIR chew-chew train?
yeah, thanks Mrs. Flo