The words ring, wring sound the same but have different meanings and spellings. Why do ring, wring sound the same even though they are completely different words?
The answer is simple: ring, wring are homophones of the English language.
A circular object, form, line, or arrangement with a vacant circular center.
A small circular band, generally made of precious metal and often set with jewels, worn on the finger.
A circular band used for carrying, holding, or containing something: a napkin ring.
Sports A pair of circular metal bands suspended in the air for gymnastic exercises, on which balancing and swinging maneuvers are performed while holding the bands as motionless as possible.
To twist, squeeze, or compress, especially so as to extract liquid. Often used with out.
To extract (liquid) by twisting or compressing. Often used with out.
To wrench or twist forcibly or painfully: wring the neck of a chicken.
To clasp and twist or squeeze (one's hands), as in distress.
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").