I hope there are some Webtrends Analytics experts on SO who can answer this question.
Once upon a time, Google Analytics had a Unique Visitors metric. Maybe around the year 2013 or 2014, Unique Visitors became Users. And Visits became Sessions.
In Webtrends Analytics, they define the terms Visits, Visitors, and Unique Visitors (see https://producthelp.webtrends.com/explore/glossary/ for more information). However, in their Visitors Dashboard, under Visitor Summary, they use the term Visitors. I cannot find any dashboards or reports which employ the term Unique Visitors. With that being said, how do I interpret the Visitor value in the Visitors Dashboard? Is it the number of unique visitors in a given time period? If the answer is yes, then it's equivalent to the Google Analytics Users metric.
Also for Webtrends Analytics, can the number of visitors be inflated if the only means of distinguishing a visitor is the client IP address + browser user agent string pair?
Thank you for your help in advance.
The link you provided is a glossary, like a dictionary for their site. It is not a definition of the metrics that's in webtrends. For your purpose, Unique visitors and visitors are the same. It is the equivalent of users in GA (basic installation, with user-id enabled, GA does session unification)
In webtrends, the detection is based on cookie, so yes, it can be inflated.