Project Team Members can all collaborate on the same document, at the same time, thanks to SharePoint's co-authoring capabilities.
Task members can have separate portions of a project document assigned to them and can open their allocated tasks simultaneously in order to add or update content.
The task bar indicator shows the number of users currently collaborating on the same document, along with a detailed message:
The status bar will indicate when Updates to the document are available.
Saving your document will fetch your the changes and merge them into your copy of the document.