The Spanish word 'carta' (meaning 'letter' or 'card') traces back through Latin 'charta' (meaning 'paper' or 'document') to Ancient Greek. In Greek, the word 'khartes' (χάρτης) meant a 'papyrus leaf prepared for writing.' This Greek word itself came from the verb 'kharassein' (χαράσσειν), which meant 'to make incisions' or 'to engrave.' This etymology reflects how early writing involved making marks or incisions on materials, before eventually coming to refer to the writing material itself and then to specific types of written documents.

Several common Spanish words are related to 'carta', including 'cartel' (poster or sign), 'cartón' (cardboard), and 'cartera' (wallet or briefcase). All these words share the basic concept of something made from or related to paper or documents.

English has many cognates derived from the same root as 'carta', including 'chart', 'card', 'charter', and 'cartography' (map-making). The connection is clear when you consider that all these words relate to paper, documents, or writing. Even the word 'character' (both in the sense of a written symbol and a person's nature) comes from the same Greek root 'kharassein', referring to the idea of something being engraved or marked.