Color Management, in digital photography, is the control of how colors are represented on your input (camera) and output devices (printer, computer display).
If all of your devices are properly calibrated, then the colors should look the same on each device. A picture should look the same on your monitor as it does when you print it.
I wasn't going to discuss color management, but it was recently brought home to me how important it is if you want consistent results. I had calibrated my old 21" CRT monitor, and when I edited photos then printed them on my Epson printer (using the profiles that came with the printer), the resulting prints looked very close to what I saw on the monitor.
Then I bought a new computer. It came with a very nice 24" LCD monitor. And, it came with Windows Vista. My old calibration software wouldn't run on my shiny new computer.
The first thing I noticed was how bright all my pictures looked. The colors were vibrant. Whites (and near-whites) were bright. Maybe too bright (that should have been a clue). I had a few recent photos I wanted to print, but they needed a bit of tweaking. So I tweaked. I cropped and made them look good on this monitor. Then I printed them.
The prints were dull and gray - not what I had come to expect from this printer. But, it was not the printer's fault. It was my overly-bright monitor. Because the monitor was so bright, when I made the photos look "correct" on the monitor they were too dark when printed on my printer. Yes, the new calibration software is on its way. I'll report on the results as soon as I can.
Update: Even after calibrating the monitor with my new software, it seems too bright. More to come...