How to Comment on a GitHub Issue?

Issues are like emails, except they can be shared and discussed more broadly.  Most software projects have a bug tracker of some kind. GitHub’s tracker is called Issues, and has its own section in every repository.  However, you can also use GitHub Issues to review developments of models and/or ask questions.  By using @mentions and references inside of Issues, you can notify other GitHub users & teams, and cross-connect issues to each other. These provide a flexible way to get the right people involved to resolve issues effectively, and are easy to learn and use

To comment on an issue, go to the bottom of an issue and “Write” a comment, and press “Comment” when complete.