The words carat, caret, carrot, karat sound the same but have different meanings and spellings. Why do carat, caret, carrot, karat sound the same even though they are completely different words?
The answer is simple: carat, caret, carrot, karat are homophones of the English language.
A unit of weight for precious stones, equal to 200 milligrams.
Variant of karat.
A proofreading symbol (‸) used to indicate where something is to be inserted in a line of printed or written matter.
A biennial Eurasian plant (Daucus carota subsp. sativus) in the parsley family, widely cultivated as an annual for its edible taproot.
The usually tapering, elongate, fleshy orange root of this plant, eaten as a vegetable.
Queen Anne's lace.
A reward offered for desired behavior; an inducement: "The U.S. should use a moratorium on SDI development as a carrot to bring an acceptable offensive arms limitation” ( C. Peter Gall).
A unit of measure for the fineness of gold, equal to 1/24 part. Pure gold is 24 karat; gold that is 50 percent pure is 12 karat.
Definitions from The American Heritage® Dictionary of the English Language, 4th Edition and Wordnik.
Homophones (literally "same sound") are usually defined as words that share the same pronunciation, regardless of how they are spelled.
If they are spelled the same then they are also homographs (and homonyms); if they are spelled differently then they are also heterographs (literally "different writing").