The words picks, pix, pyx sound the same but have different meanings and spellings. Why do picks, pix, pyx sound the same even though they are completely different words?
The answer is simple: picks, pix, pyx are homophones of the English language.
Plural form of pick.
Third-person singular simple present indicative form of pick.
A plural of pic.
Variant of pyx.
Ecclesiastical A container in which wafers for the Eucharist are kept.
Ecclesiastical A container in which the Eucharist is carried to the sick.
A chest in a mint in which specimen coins are placed to await assay.
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.