From Diablo Wiki
The character window in Diablo 3 is merged with the Inventory and Paper Doll display, providing a quick and convenient view of your character's equipment and stats in one location. A mini-window is shown beside the paperdoll with a "Details" button to expand a comprehensive list of dozens of character stats and values.
The character window changed repeatedly during development, right up until development. One major innovation was combining the character window with the inventory window, a shift made possible by the removal of the Talisman feature.
Other Diablo 3 GUI elements:
Character Window Evolution
The character window evolved continuously during the game's development, with a total remodel taking place during the beta test and additional figures being added to the display post-release. Though it's undergone numerous tweaks, the character window has always listed the attributes, resistances, damage, armor, and other essential stats.
The final game version shows a miniature window as part of the Inventory window. When players click the "Details" button the full list of stats for Offensive, Defensive, Life, opens up beside the window, and can be scrolled down to see every relevant figure. This information display is quite comprehensive and though a bit eye-glazing for new players, the information shown therein is very useful once players know what to do with it.
Diablo 3's character window shows a great deal more information than players saw in Diablo 2, and the stats and figures displayed by the game are [[black weapons|almost) entirely correct, which was very not the case with Diablo 2's so-called.
A collection of views of the Character window, showing how it evolved during development. Blizzard did not release many images of this interface early in development, so most of the older pictures blurry photos taken of monitors at gaming shows and other events.
Character and Inventory windows, Blizzcon 2010.