The words chary, cherry sound the same but have different meanings and spellings. Why do chary, cherry sound the same even though they are completely different words?
The answer is simple: chary, cherry are homophones of the English language.
Very cautious; wary: was chary of the risks involved.
Not giving or expending freely; sparing: was chary of compliments.
Any of several trees or shrubs of the genus Prunus, especially P. avium or P. cerasus, native chiefly to northern temperate regions and having pink or white flowers and small juicy drupes.
The yellow, red, or blackish fruit of any of these plants.
The wood of any of these plants, especially black cherry.
Any of various plants, such as the Barbados cherry or the cornelian cherry, having fruits resembling a cherry.
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").