Domain hijacking is the process of transferring ownership of a domain name without the permission of the registrant (domain owner). This is usually done by hacking into their registrar account or tricking them into giving away their password, by pretending to be their registrar.
Reverse domain hijacking is where someone tries to claim the rights to a domain and use legal threats or UDRP (Uniform Domain Name Resolution Policy) action to have a domain transferred to them from the current owner who also has full right to own and the same domain.
