Every day, thousands of people are having conversations on GitHub around code, design, bugs, and new ideas. Sometimes there are complex and nuanced points to be made, but other times you just want to 
someone else's comment. We're adding Reactions to conversations today to help people express their feelings more simply and effectively.
While people have been able to include emoji in responses for a long time, using them as reactions resulted in a lot of noise. In many cases, especially on popular projects, the result is a long thread full of emoji and not much content, which makes it difficult to have a discussion. With reactions, you can now reduce the noise in these threads.
We decided to choose reactions that are relevant to the conversations people have on GitHub. 
cover the range of reactions our users typically express through comments on GitHub. We’re looking forward to seeing how the GitHub community uses this set of reactions.
Reactions are available on all Issues and Pull Requests on GitHub today. So go ahead… or to your s content.