Users without Google accounts will be able to view, comment, suggest edits to, and edit Google Docs, Sheets, and Slides files. This is still part of a beta program and is available to all G Suite editions, but for now only on Google’s invitation. G Suite admins can apply here.
According to Google, In this beta there is a pincode identity verification process that will enable G Suite users to invite non-G Suite users to collaborate on files as visitors, using PINs (Personal Identification Numbers).
File owners and admins are in control of sharing and can view all the detailed activity on their files and see where it originated, and revoke access from the Drive sharing dialog at any time.
G Suite admins can manage all external sharing and audit usage.