As shown below, Tabs Panel is one of the three major panels inside the main screen. When you open any subscription to see its retreived content, or new webpage to browse, they are shown inside tabbed-windows in the Tabs Panel.
Apart from the area where content is shown, each tabbed-window has two more parts; those are its caption and toolbar, as described shortly below.
Tab caption includes title of the shown page and two buttons to close and maximize that window. When tab is maximized, other two major panels of the main screen, namely Subscriptions and Functions panel, are minimized in order to leave more room for that maximized window.
In the sample screenshot above, you can also see another unique feature of the tab caption which is that it show progress level of page load. This helps you decide when to switch to that tab in order to see its content, that is, when it is fully loaded.
Located at the bottom of the tab caption, toolbar presents all necessary functions for navigation as in the case of your web browser. Those functions include back and forward buttons, buttons to stop page loading and to refresh shown page, as well as an edit field to show the address of the shown content.
However, based on the type of shown content, functions provided by the toolbar varies. For example, shown toolbar above is the toolbar of the tab which shows a webpage inside.
To learn more about toolbars, check the corresponding help topic.