These two “A”s look identical on screen, but if they were printed out in CMYK settings, they would actually not look the same!
Here’s what they look like with a preview of how the actual print would come out:
The actual color for the “A” on the top is 100% black, no other inks:
The one on the bottom is a Rich Black, which means it has cyan, magenta, and yellow inks layered with the black:
100% black can often appear almost like a charcoal gray in print.
100% black is appropriate for printing text and small, intricate details, while rich black is appropriate for printing large blocks of color that need to have depth to them.