A traditional piercing goes straight through the skin, but a dermal piercing is trapped between tissue. The piercer makes a small incision with a needle, then they slip the jewelry into the skin. Picture putting your foot into a shoe—you put in your toes first, then you slip in your heel. It's a similar concept, where we first put in the 'toe' of the jewelry, then pop the 'heel' into place. That anchors the decorative piece in place above the skin.