Homonyms can be separated into two groups, homographs (same spelling) and homophones (same sound).
Example
‘Write', ‘right' and ‘rite' are examples of homophones, and ‘wind' is a homograph with several meanings (‘wind the clock' ‘a howling wind').
In the classroom
There are various useful learning opportunities associated with homonyms. For example, learners can better understand the difference between English spelling and pronunciation by looking at homophones, and homonyms can be a good way of showing the usefulness of phonemic script.
Further links:
https://www.teachingenglish.org.uk/article/same-sound-different-sound
https://www.teachingenglish.org.uk/article/homophone-game
https://www.teachingenglish.org.uk/article/homophones-dictation