what's windows registry?

An introduction to Windows registry can be found here:

http://pcsupport.about.com/od/termsr/p/registrywindows.htm

"The Windows Registry is used as a single place to store much of the information and settings for software programs, hardware devices, user preferences, operating system configurations, and much more.
In many ways, the registry can be thought of as a kind of DNA for the Windows operating system."