WHOIS is a public lookup that shows who a domain is registered to and how to contact them. It's also known as RDAP.
For most extensions, including .com, personal details such as your name, address, phone number and email address are already hidden from public WHOIS results. The public record usually shows only:
Privacy protection goes a step further by replacing your remaining details with those of a privacy service. Messages sent to the published address are forwarded to you, so people can still reach you without seeing your email address.
Privacy protection is free on every extension that allows it. To turn it on, go to Domains in the Client Area, click Manage beside the domain and turn on privacy protection.