The words read, rede, reed sound the same but have different meanings and spellings. Why do read, rede, reed sound the same even though they are completely different words?
The answer is simple: read, rede, reed are homophones of the English language.
To examine and grasp the meaning of (written or printed characters, words, or sentences).
To utter or render aloud (written or printed material): read poems to the students.
To have the ability to examine and grasp the meaning of (written or printed material in a given language or notation): reads Chinese; reads music.
To examine and grasp the meaning of (language in a form other than written or printed characters, words, or sentences): reading Braille; reading sign language.
To give advice to; counsel.
To interpret; explain.
Advice or counsel.
Archaic A narration.
Any of various tall perennial grasses, especially of the genera Phragmites or Arundo, having hollow stems, broad leaves, and large plumelike terminal panicles.
The stalk of any of these plants.
A collection of these stalks: reed for making baskets.
Music A primitive wind instrument made of a hollow reed stalk.
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").