This is Google's official URL shortcut service that provides shortened links exclusively for Google websites and products. The g.co domain serves as a trusted redirect system that ensures users are directed to legitimate Google services when they encounter these shortened URLs.
The service functions as a security and convenience feature, allowing users to confidently click on g.co links knowing they will only lead to authentic Google destinations. It represents Google's commitment to user safety by preventing phishing attempts and ensuring reliable access to their ecosystem of products and services.