The words auk, awk sound the same but have different meanings and spellings. Why do auk, awk sound the same even though they are completely different words?
The answer is simple: auk, awk are homophones of the English language.
Any of several diving sea birds (family Alcidae) of northern regions, such as the razor-billed auk, having a chunky body, short wings, and webbed feet.
Odd; out of order; perverse.
Wrong, or not commonly used; clumsy; sinister; as, the awk end of a rod (the butt end).
Clumsy in performance or manners; unhandy; not dexterous; awkward.
Perversely; in the wrong way.
Definitions from The American Heritage® Dictionary of the English Language, 4th Edition, 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").