Domain privacy is an advantage that can help you avoid unsolicited queries, spam, and phishing attacks. It can reduce much of the spam emails that you would get otherwise. It's an inexpensive way to keep your data private where WHOIS data is open to the public.
Domain name registrars offer domain privacy service for security of domains. Most of the companies sell privacy to their users, and in turn, replace the user’s information in WHOIS along with the forwarding service information. The database which contains information about your domain such as its registrar, name server, full name and others is term as WHOIS. The WHOIS database contains all the contact and other information related to domains.