Letters

Because they are

“Letter,” borrowed from Old French lettre, entered Middle English around AD 1200, eventually displacing the native English term bocstaf (i.e. bookstaff). Letter derives from Latin littera, which may have derived, via Etruscan, from the Greek “διφθέρα” (writing tablet).

The Middle English plural lettres could refer to an epistle or written document, reflecting the use of the Latin plural litteræ. Use of the singular letter to refer to a written document emerged in the 14th century.

A letter is a grapheme

in an alphabetic system of writing

DEFINITION AND USAGE
“The pen is an instrument of discovery rather than just a recording implement. If you write a letter of resignation or something with an agenda, you’re simply using a pen to record what you have thought out.”Billy Collins
Izstrādāja KM DEVELOPMENT