The words c, cee, sea, see sound the same but have different meanings and spellings. Why do c, cee, sea, see sound the same even though they are completely different words?
The answer is simple: c, cee, sea, see are homophones of the English language.
The third letter of the modern English alphabet.
Any of the speech sounds represented by the letter c.
The third in a series.
Something shaped like the letter C.
The letter c.
The continuous body of salt water covering most of the earth's surface, especially this body regarded as a geophysical entity distinct from earth and sky.
A tract of water within an ocean.
A relatively large body of salt water completely or partially enclosed by land.
A relatively large landlocked body of fresh water.
see about To investigate.
To perceive with the eye.
To apprehend as if with the eye.
To detect by means analogous to use of the eye: an electronic surveillance camera that saw the activity in the embassy yard.
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").