For full disclosure, I’ve sourced this description from Wikipedia. It give a very plain text definition of the process, and hey, why reinvent the wheel!!!
Intaglio is the family of printing and printmaking techniques in which the image is incised into a surface and the incised line or sunken area holds the ink. It is the direct opposite of a relief print.
Normally, copper or zinc plates are used as a surface or matrix, and the incisions are created by etching, engraving, drypoint, aquatint or mezzotint. Collagraphs may also be printed as intaglio plates.[