The words whined, wind, wined, wynd sound the same but have different meanings and spellings. Why do whined, wind, wined, wynd sound the same even though they are completely different words?
The answer is simple: whined, wind, wined, wynd are homophones of the English language.
Simple past tense and past participle of whine.
A single turn, twist, or curve.
near the wind Close to danger.
Moving air, especially a natural and perceptible movement of air parallel to or along the ground.
A movement of air generated artificially, as by bellows or a fan.
Simple past tense and past participle of wine.
A narrow lane, alley or path, especially one between houses.
Definitions from Wiktionary, Creative Commons Attribution/Share-Alike License, 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").