From Paterva Wiki
A domain is the 'cnn.com' part of 'www.cnn.com'. It is the 'google.com' part of 'www.google.com'. A domain has to be registered by a person or an organisation. A domain is registered in a TLD (top level domain), and might have a SLD (sub level domain). Consider the web site 'www.abc.co.uk'. The top level domain (TLD) is 'uk'. The sub level domain is 'co.uk'. The domain itself is 'abc.co.uk'. A domain contains whois information - this information contains (at least) the details of who registered the domain.
Learn more about this entity
Domain name on Wikipedia
See also (other entities)
Properties of this entity in Maltego
(whois) Additional to the value (which is the domain's name) whois information is also stored. This information is only obtained once a transform requests it.