As a practical matter, what is the difference between sending & receiving texts from AOL mail vs. AIM? Thank you.
Instant messaging lets you see that the other person is typing (or not). Also the whole conversation is displayed, and you can scroll back, so you don't get lost among many messages trying to figure out which question is being answered. You can log the conversation and save it to a file, rather than trying to piece it together from many messages.
But IM doesn't automatically get saved on either end, so if you want a record of something promised, better confirm with email.