Parked Domains
The aim of parked domains is to make some money from different online advertising platforms. Parked domains do not point to any website or to any email server. They are bought and hooked up with advertising portals so that if anyone typed the domain name in the address bar of their browser, it would show some advertisements relevant to the browsing history of the user. People buy plenty of domain names and park them so that they could earn some money. Another aspect of buying domains and parking them somewhere is to sell the domain to the highest bidder. This type of activity is called cybersquatting. People buy domain names that appear to be of high value. Those domains are bought and then parked. People who want to buy the domain, negotiate with the owner and if mutually agreed on monetary compensation, a deal is made to transfer the domain URL to the buyer. In short, parked domains are not websites. They refer to a set of advertisements. If anyone wants to buy already parked domains, they have to contact the parked domain owner. If the intention is to sell the domain, sellers’ contact information is either on the parked page or on WhoIS.
Sinkhole Domains
Sinkhole domains are actually DNS computers that mislead your data packets to some sites other than where you wish to go. DNS servers are Domain Name System servers. These servers are responsible for loading your web pages. When you type any URL in the address box of your browser, the URL is converted into an IP (Internet Protocol) address. The URL is searched in the HOSTS file in the Windows folder first. If it already has the website address, the page will load without any problems. In case the HOSTS file doesn’t contain the address, they reach DNS computers, and the address is noted down to create a connection between that website and your computer. Sinkhole domains are created and used by cybercriminals to steal your data. Since the entire Internet is dependent on Domain Name Servers (DNS) for the resolution of Uniform Resource Locators (URL), it can be hacked and used for redirecting users to other, similar-looking websites for Phishing purposes. Phishing is an attempt to get your details using unfair means. Read the linked article: all about Phishing, to know more. Summary I hope this explains the subject.