How to chat with your co-editors in real-time in Office Online?

As the name suggests, Office Online is an online office suite that helps the users create, edit and share the files over web. This is possible by using the lightweight web-browser versions of Office applications, including Word, Excel, OneNote and PowerPoint. This feature is also available in Office 365 as well. The Office Online feature is helpful for the business and education clients who have shared/stored their documents in OneDrive for business or SharePoint Online.