tab has all users on your website displayed in a list.
Here you see their email, bids, auctions and ratings. The Bid Blocked column allows you to block that user from bidding on auctions. Clicking on the user name will take you to that users details page.
On the details page you can see all the details that user has provided along with the time he has been a member of the site, his rating, statistics and some information about hist recent bids and auctions.