movable type

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Type in which separate pieces of hard material, usually metal, are positioned in a rack to compose the lines on a page. Movable type was invented independently in China and Europe and made possible the widespread dissemination of information through the production of large numbers of identical documents.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A system of printing and typography that uses movable components such as individual letters or punctuation to reproduce the elements of a document.