The words reck, wreck sound the same but have different meanings and spellings. Why do reck, wreck sound the same even though they are completely different words?
The answer is simple: reck, wreck are homophones of the English language.
To take heed of or to have caution.
Something shattered or dilapidated.
The remains of something that has been wrecked or ruined.
The act of wrecking or the state of being wrecked; destruction.
Accidental destruction of a ship; a shipwreck.
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").