what do we understand by the uniqueness of the linking domain?

[Kailash]

what do we understand by the uniqueness of the linking domain?

[Pihu]

Linking Domains -Number of unique root domains linking to a target. Two links from the same website will only be counted as one linking root domain. Inbound Links (backlinks) - An incoming link from a page on another website back to your own site.

[himanshu]

When a site links to another one or more than one time in Search Engine Optimization, site A is said to be a linking root domain; the plural, linking root domains is the total number of separate links that link once or more than once to a given site.

[rscomponentseo]

Your number of Linking Root Domains includes the number of unique root domains linking to a site. Two links from the same website would only be counted as one Linking Root Domain. This includes followed and nofollowed links.