Whois is a protocol used for retrieving information about the domain name registered with the Internet Corporation for Assigned Names and Numbers (ICANN). It was first introduced in 1982 and is still widely used today.

The Whois database contains essential data about every domain name registered, including the name and contact details of the domain owner, the name server, the registration and expiration dates, and relevant administrative and technical contacts.

The Whois protocol facilitates access to this information by allowing anyone to query the database by submitting the domain name or IP address.

There are several reasons why someone may need to use Whois. For instance, it can be useful for:

1. Verifying domain ownership: As a domain owner, it’s essential to confirm accurate registration details. Whois enables you to confirm that your domain is registered to the correct name, address, and email address.

2. Protecting your brand: Whois can help you monitor your brand and ensure that no one else is using your trademark or brand name.

3. Investigating possible fraudulent activity: Whois can be used by law enforcement agencies to investigate suspicious domains or websites for possible fraudulent, malicious, or illegal activities.

4. Researching domain availability: If you are interested in purchasing a domain name, Whois can provide you with crucial information about its availability and registration details.

Whois has undergone various changes over the years, with the latest being the General Data Protection Regulation (GDPR). The GDPR was implemented in May 2018 and aimed to enhance data protection and privacy rights for European Union citizens. As a result of the GDPR, many domain registrars now offer privacy protection for domain owners who are concerned about their details being publicly available.