For those times when you make a mistake or just change your mind, you can now edit your sent messages. A simple spelling mistake or some more context. It will all be possible.
Soon you will be able to adjust the text by pressing longer on a message. Although that is only possible in the first 15 minutes after sending the message. Such a modified message will also show that it has been edited.
WhatsApp has started rolling out the feature globally and everyone will be able to use it in the coming weeks.