The words wails, whales sound the same but have different meanings and spellings. Why do wails, whales sound the same even though they are completely different words?
The answer is simple: wails, whales are homophones of the English language.
To grieve or protest loudly and bitterly; lament. See Synonyms at cry.
To make a prolonged, high-pitched sound suggestive of a cry: The wind wailed through the trees.
Archaic To lament over; bewail.
A long, loud, high-pitched cry, as of grief or pain.
Bay ofWhales An inlet of the Ross Sea in the Ross Ice Shelf of Antarctica. It has been used as a base for Antarctic expeditions since 1911.
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").