It was originally known as The Association of Public Radio Stations and National Educational Radio Network.
It airs many news and cultural programs. Here is a list of some of them:
All Things Considered, which is hosted by Robert Siegel, Michele Norris, and Melissa Block. This program is considered NPRs flagship news program and is the highest rated public radio program.
Talk of The Nation, which is hosted by Neal Conan. This program focuses primarily on current events and controversial issues and regularly includes special guests along with a call-in format.
All Songs Considered, which is hosted by Bob Boilen. This is the flagship program of NPR's music format. It features information and streaming audio of unsigned and unknown bands as well as some well known acts.
Car Talk, which is hosted by Tom Magliozzi and Ray Magliozzi. This program discusses hints and tricks on auto repairs and is a call-in structure.
On a personal note, lately I tend to read a lot of my news from NPR because I find it, in my opinion, to be less biased than other forms of media. In fact, because of the lack of quality music stations in the Oklahoma City area (again, my opinion), I have found myself listening to NPR more often in my car lately.
Give them a listen sometime.
In the Oklahoma City area, you can hear NPR on 105.7, 90.1, 106.3, and 91.7.