There are many ways to forward traffic from one domain/website to another. The so-called URL redirection is frequently preferred. In contrast to parking a domain address, a URL redirection can be done only if the domain in question is hosted. What this means essentially is that you could still open any content if you have a direct link to it and you could create e-mail addresses or subdomains and use them. Such a function has lots of practical uses - if you choose to switch your domain, you could forward the site visitors, but the e-mails with the old one shall still be active whenever you are getting in touch with clients or partners. If you have 2 identical sites and you would like to rebuild one of them, you could forward the traffic to the other website to avoid losing potential clients, while you shall still be able to access the administration area for the first site and work on it.