When Vista was released to the public, it featured a brand new DirectX version. DX 10.0 allowed Vista to look and feel different from XP in several ways. The introduction of the Aero theme provided users with a very clean look through transparencies in both the start bar and any windows that were opened.
Vista also introduced the sidebar. Although the sidebar was replaced in Windows 7 by the ability to add widgets anywhere on the screen for increased personalization of the OS, the sidebar was an incredible tool for anyone that wanted important RSS feeds to be on the desktop. Those looking beyond functionality found that the ability to add pictures or simple reminders to the sidebar provided them with a level of customization they'd never experienced before.