Microsoft Loop is a new app and set of functionality coming in the upcoming months to provide new real-time collaboration capabilities.
Loop Workspaces allow you to manage content in a dedicated space. A dedicated app will be coming later.
Loop Pages are canvases within Workspaces where you can use multiple components.
Loop Components are collaborative building blocks including lists, text, tables, images, and comments.
The most remarkable thing about components is that they are available in other applications, like Microsoft Teams, Outlook, and OneNote.
Microsoft Loop depends on OneDrive for Business to store files and syncing. Unfortunately, guest users cannot participate at this time.
Microsoft Loop Components are now available in preview with Microsoft Teams chat.