Arc is a video tool that allows users to post and/or create a video that others can view and make comments on, in real-time, within the timeline of the video. Replies to comments are nested within the video, allowing you to see the conversation unfold and learn from each other's insights, as well as get feedback and direction. 

This tool allows instructors and students to actively collaborate through video in all elements of Canvas with a Rich Content Editor (Pages, Discussions, Assignments, etc).