Affirmation of a post by another user.

The Facebook like button is designed as a hand giving “thumbs up”. It was originally discussed to have been a star or a plus sign, and during development the feature was referred to as “awesome” instead of “like”. It was introduced on 9 February 2009.^[4] During May 2016, Facebook introduced reactions – a new way to express peoples emotions to Facebook posts. Some reactions included “Love”, “Haha”, “Wow”, “Sad”, or “Angry”. – Source: Wikipedia