What is digital photography?
Photography literally means painting with light. Digital photography is essentially the act of painting with light onto a digital sensor. It is essentially the same thing as traditional film photography, except for the fact that, instead of having a piece of side film in the back of your camera, it's actually replaced with an electronic sensor that acts in a very similar way. Benefits of that include being able to the grain quality, ISO, and just being able to suck in more light as the technology gets better.
Some other benefits of digital photography include instant gratification. You can immediately see the image you just took on the back of your screen. It makes learning photography in general much quicker because you immediately know where you went wrong, instead of having to wait for the film to be processed and the prints to make.
Since the dawn of digital photography, which a lot of people will say really caught on in about 2001 as digital cameras got to the point where they began to surpass the quality of film, we've seen a rapid increase of digital cameras, the exposing of digital camera technology. Prices have come down. Quality has gone up. While this camera might cost $3,000, you can easily go to the store and get a high quality digital camera for $200.
That's a basic introduction to digital photography.