There are exist one computer with installed TFS. I open the admin console, but didn't see any license information. So how to identify which type of license it have?Answer1:
Select the root node on the left panel <a href="https://i.stack.imgur.com/2SWiq.png" rel="nofollow"><img alt="enter image description here" class="b-lazy" data-src="https://i.stack.imgur.com/2SWiq.png" data-original="https://i.stack.imgur.com/2SWiq.png" src="https://etrip.eimg.top/images/2019/05/07/timg.gif" /></a>
If you have a trial, you see a <strong>License Expires</strong> item, with the option to change the Product key (see <a href="https://msdn.microsoft.com/en-us/library/cc668758(v=vs.120).aspx" rel="nofollow">Locate or Change the Product Key</a>). This is for the <em>Server</em> license.
Client licenses or CAL are not so simple, they are personal and not all users requires one. See <a href="https://www.visualstudio.com/docs/work/connect/change-access-levels" rel="nofollow">Access Levels</a> and <a href="https://www.microsoft.com/en-us/download/details.aspx?id=13350" rel="nofollow">2015 licensing white paper</a> for details. It is up to the administrator to make sure that users have the proper access for their requirements and license.