What is the ‘tab’ element of a skin?

The tab element is a panel that shows different elements depending on which tab you select. The container panel has tabs on the top with customizable titles. The appearance of each tab is also customizable in color, size, font etc. This is very useful if you wish to have different thumbnail lists divided by type of media, for instance. In each tab you could group one type of media (panoramas, videos, photos).