Here's how it works: after you upload a video, YouTube will scan other videos uploaded to YouTube to see if any of them are the same or very similar. When there is a match, it will appear in the "matches" tab in the tool and you can decide what to do next. Youtube says it has been testing this tool with creators for nearly a year.
This tool is intended to find full re-uploads. If you find a clip of your content that you'd like removed, you can always report it via the copyright webform.
Once the tool has found a match, you can choose either to do nothing, to get in touch with the other creator, or request that YouTube remove the video. When you request removal you can do so with or without a 7-day delay to allow the uploader to correct the issue themselves. Takedown requests will be reviewed to make sure they comply with YouTube's copyright policies.
The Copyright Match Tool does use similar matching technology used by Content ID, but the Copyright Match Tool is a unique tool designed especially for YouTube creators who have problems with unauthorized re-uploads.
Next week, Youtube promised to start rolling this tool out to creators with more than 100k subscribers. Youtube will monitor usage and will continue to expand over the coming months with the long-term goal of making it available to every creator in the YouTube Partner program.