While your computer screen shows color by projecting combinations of red, green, and blue (RGB), your printer creates color by printing color inks onto paper.
Typically the inks used are cyan, magenta, yellow, and black (CMYK), but can include light versions of cyan, magenta, and black inks or sometimes red and blue or orange and green. To achieve a color match from your monitor to your printer the monitor and printer must both be calibrated and profiled.
When you calibrate your printer you are essentially setting it up for optimum ink distribution on paper. Calibration ensures linear progression of the ink tints from 100% to 1% without a tonal distortion. Calibration also ensures you are getting the best color saturation for vivid color prints. Because each paper absorbs ink differently you must create a seperate calibration for each paper you use.
To achieve the best results a Raster Image Processor (RIP) is recommended. A RIP allows you to communicate to the printer in CMYK rather than RGB as is the case with manufacturer print drivers. Profiling your printer allows a color management system to correctly translate colors to your paper.