The words where's, wares, wears sound the same but have different meanings and spellings. Why do where's, wares, wears sound the same even though they are completely different words?
The answer is simple: where's, wares, wears are homophones of the English language.
Plural form of ware.
Goods or services that are for sale.
Plural form of wear.
Third-person singular simple present indicative form of wear.
Contraction of where is.
Contraction of where has.
Contraction of where does.
Definitions from Wiktionary, Creative Commons Attribution/Share-Alike License 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").