to me the terms mean the same.
What am I missing?
calibration means (here) that 1.) the grey scale is adjusted via graphic card / video LUT according to the white point and the gamma and
2.) that the colour reproduction of the display is measured and stored in a profile. The second part is "profiling": the characterization of the display without previous adjustment of the grey scale.
The Dell displays are quite bright even when adjusting to the lowest level. Too, they are quite cold and tend to have a shift to green. That's what I've heard about the Dell displays... So I think it's essential to calibrate it just as you are used to do it with your CRT. (In this case you have to reduce the blue and the green chanel in the OSD and you will lose some tonal values as the display has just an 8bit LUT).If
the Dell is calibrated quite well out of the box you will not lose that much tonal values due to the grey scale calibration as in this case the corrections on the graphic card will be marginally.
A colleague has 2 or 3 of those Dells amongst Highend displays in a prepress agency. They don't use them for final production but preproduction of certain stuff. They are calibrated of course. He said they are quite good for the price but of course have some banding in dark tonal values after calibration. As long as banding is visible only in technical test patterns like gradations and such but not in real images that's okay. That's the price you pay for the cheaper display.
The loss of gamut (when reducing certain colour chanels) is totally negligible... an accurate white point is much more important than a slightly bigger gamut.
Too I find an accurate grey scale essential... to me it's actually the most essential thing and it is basically what is calibration all about.