The words sol, sole, soul sound the same but have different meanings and spellings. Why do sol, sole, soul sound the same even though they are completely different words?
The answer is simple: sol, sole, soul are homophones of the English language.
Music The fifth tone of the diatonic scale in solfeggio.
An old French coin worth 12 deniers.
See Table at currency.
A colloidal solution.
The underside of the foot.
The underside of a shoe or boot, often excluding the heel.
The part on which something else rests while in a vertical position, especially:
The bottom surface of a plow.
The animating and vital principle in humans, credited with the faculties of thought, action, and emotion and often conceived as an immaterial entity.
The spiritual nature of humans, regarded as immortal, separable from the body at death, and susceptible to happiness or misery in a future state.
The disembodied spirit of a dead human.
A human: "the homes of some nine hundred souls” ( Garrison Keillor).
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").