What is backbiting in Islam? How much are you aware of such an evil deed, and its consequences? What does God say about it?

God says:

O you who believe! Shun much suspicion. Verily! Some suspicion is a crime. And spy not, neither backbite one another. Would one of you love to eat the flesh of his dead brother? You would hate it (so hate backbiting)! And keep your duty (towards Allah). Verily! Allah is Relenting, Merciful. (Al-Hujurat 49:12)

So, how can we stop backbiting?