Definition:
Formal: “relating to or involving the outward form, structure, relationships, or arrangement of elements rather than content”
“Formal.” Merriam-Webster.com, 2022, www.merriam-webster.com/dictionary/formal.
Informal: “characteristic of or appropriate to ordinary, casual, or familiar use”
“Informal.” Merriam-Webster.com, 2022, www.merriam-webster.com/dictionary/informal.
Informal Definition:
Formal: Following a pre-established structure or ruleset, usually in order to better organize the content.
Informal: Casual speech, not relying on precise rules or structure.
Etymology:
Formal (adj.): late 14c., "pertaining to form or arrangement;" also, in philosophy and theology, "pertaining to the form or essence of a thing," from Old French formal, formel "formal, constituent" and directly from Latin formalis, from forma "a form, figure, shape". From early 15c. as "in due or proper form, according to recognized form," As a noun, c. 1600 (plural) "things that are formal;" as a short way to say formal dance, recorded by 1906 among U.S. college students.
Harper, Douglas. "formal (adj.)." Online Etymology Dictionary, 8 Aug. 2008, www.etymonline.com/search?q=formal+diction. Accessed 6 Sept. 2022.