Jim,
In simple terms a format using a laser at the blue light wavelength. Laser on this wavelength allows very high density of the media so in other words a lot of data in the same surface area.
Think of it like a CD to DVD, bluray is that much higher factor again.
I just got myself a bluray been waiting for prices to drop. Cost me just on 200
It's only profile 1.1 but that is all I want, plays zone A B and C. If I want to read about a movie I will look it up on IMDB.