Visitor Major DomainsThis display lists the major root domains (".com", ".net", ".gov", ".edu", etc.) that your visitors are registered with when they connect to the internet.
Terms Used on Report:
Also referred to as a 'Unique Visitor'. By default, this value represents a visitor that comes to your site for the first time in a day. All subsequest visits during the day by the visitor are not considered unique.
The definition of a visitor can be customized. You can set a custom period of inactivity that will cause the next access of the visitor to be considered a new visit. The visit definition screen can be found on the 'Setup' menu.
This differs from a page view or hit in that a single visitor can have one visit per day but many page views during a visit.