The words bruise, brews sound the same but have different meanings and spellings. Why do bruise, brews sound the same even though they are completely different words?
The answer is simple: bruise, brews are homophones of the English language.
Plural form of brew.
Third-person singular simple present indicative form of brew.
To injure the underlying soft tissue or bone of (part of the body) without breaking the skin, as by a blow.
To damage (plant tissue), as by abrasion or pressure: bruised the fruit by careless packing.
To dent or mar.
To pound (berries, for example) into fragments; crush.
Definitions from Wiktionary, Creative Commons Attribution/Share-Alike License, 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").