Print - A single piece of paper upon which an image has been printed from a block or other matrix.
Edition - An edition of a print includes all the impressions (on paper) published at the same time or as part of the same publishing event.
Relief - An image printed from a design raised above the level of the rest of the block. Usually the areas of a block's surface not meant to be printed are cut away (lowered) with chisels or knives, leaving the surface raised with the design to be printed.
Proof - An impression of a print made prior to the final published edition, allowing the artist to see what work still needs to be done to the block(s).
Provenance - The history of a print, including when it was purchased and by whom, and also where it has been exhibited. Provenance in older pieces often becomes hard to establish.
Key Block - The block, also called a master block, that carries the full image design and is used to print an outline of the image onto any other blocks needed to print additional colors for the image.

Excerpts from Collecting Prints, by Leila Lyons, Random House, 2006.