Project Shield will use Reverse Proxy that will allow websites to route both legitimate and attack traffic through Google's infrastructure to ultimately filters harmful traffic by absorbing it through caching.
Google team, noted that Project Shield will benefit every single users and said the service can be turned on or off as quickly as any other DNS change.
According to the blog post, Google Project Shield -
“Some Project Shield users see better website performance because of Project Shield's caching features,” - Another thing noted by team is that, site under Project Shield may seems bit slower and websites embedding videos may also affected but if the videos is from YouTube then it will work fine for its users.
Privacy with Project Shield
Those concerned with privacy should know the program collects and stores user configuration settings and logs for traffic that is proxied through Project Shield but Google says said it only uses the site reader's IP address and other information to evaluate whether traffic is an attack and only retains aggregated metrics and details about specific attacks.
If a user deletes their site from the Project Shield dashboard, their information will also be deleted from Project Shield site configuration information and the project will no longer collect traffic data from the site.
How To Apply?
Its very simple for registration of Project Shield, just click on this Application link or visit g.co/shield. After the submitting the application you will get the notification on the email you provided. Later Google team will verify your submission request, and If you are approved, you will receive an email invitation to set up your website with Project Shield.