Bartik is the default theme for Drupal 7.
A huge thank you to the dozens of people who worked on this theme, and to everyone who supported the effort.
The Bartik theme comes with several regions.
regions[header] = Header
regions[help] = Help
regions[page_top] = Page top
regions[page_bottom] = Page bottom
regions[highlighted] = Highlighted
regions[featured] = Featured
regions[content] = Content
regions[sidebar_first] = Sidebar first
regions[sidebar_second] = Sidebar second
regions[triptych_first] = Triptych first
regions[triptych_middle] = Triptych middle
regions[triptych_last] = Triptych last
regions[footer_firstcolumn] = Footer first column
regions[footer_secondcolumn] = Footer second column
regions[footer_thirdcolumn] = Footer third column
regions[footer_fourthcolumn] = Footer fourth column
regions[footer] = Footer
These can be seen in action in the following screenshot:
The primary menu appears as tabs along the top of the page, below the header.
The secondary menu appears in the upper left corner.
The color module, if enabled, can be used to change the color of several parts of the Bartik theme, including the header (as a gradient), footer, link and text color.
The Bartik theme is named after Jean Bartik, one of the original programmers for the ENIAC computer.