A facsimile is a copy or reproduction of something. Many parents hope their children will be facsimiles of themselves; many children have other plans in mind.
Facsimile comes from two Latin roots: facere, meaning "to make," and simile, meaning "like." Fax machines are so called because they copy and transmit facsimiles of documents, or faxes for short, over phone lines. Grammatically speaking, photocopiers also make facsimiles, but oddly enough those are referred to as copies — not faxes.