The words pe, pea, pee sound the same but have different meanings and spellings. Why do pe, pea, pee sound the same even though they are completely different words?
The answer is simple: pe, pea, pee are homophones of the English language.
The 17th letter of the Hebrew alphabet. See Table at alphabet.
A member of the pea family.
A Eurasian climbing annual vine (Pisum sativum) cultivated in all temperate zones, having compound leaves with terminal leaflets modified into tendrils and globose, edible seeds enclosed in a green, elongated pod.
The seed of this plant, used as a vegetable.
The unopened pods of this plant.
The letter p.
An act of urination.
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").