Many of us would have experienced this before - you type a post but just when you hit Reply, it tells you your post needs to be at least 20 characters.
Instead of just adding "this post needs to be 20 characters" (which is over 20 characters and enough for your post to be shared), let's give a thought about why there is this rule.
It's to discourage us from sharing posts that are too short and don't really add to the conversation. Examples might be "Ok", "Agreed", or "Thanks". The heart button was created for this purpose.
Hearting is a way of telling someone you agree with what they're saying, you've read their reply and want to thank them, you like what they've talked about, you like what they're doing for the community and so on.
If you want to do more than heart and reply, think if your post is adding to the conversation. You might share a new viewpoint or idea, or want to praise someone else as well, which is awesome.
But if your response is less than 20 characters long, you might want to think about what you're saying. Either see if there's anything else you could share, or if it's just a short reply to another post you might want to heart it as your response instead