Drizzt said:
What is Camera RAW anyway? Does it plug into Lightroom?
I don't mean to be belittling, so don't be offended- But to apply the cliche saying...
"If you don't know what it is, you don't need to worry about it".
Camera RAW is the file created by your camera's sensor BEFORE being compressed to JPEG. These files are uncompressed (on most cameras), have no white balance applied to them, have more pixel depth, and allow much more headroom for post alteration. If you shoot in RAW, you can adjust almost any small to medium exposure issues you had, get a much broader range for white balance adjustment, and overall just have more legroom. However, as these are uncompressed, they tend to be quite large. A RAW file from a 12mpx Nikon D2X is 20mb.