The words tense, tents sound the same but have different meanings and spellings. Why do tense, tents sound the same even though they are completely different words?
The answer is simple: tense, tents are homophones of the English language.
Tightly stretched; taut. See Synonyms at stiff, tight.
In a state of mental or nervous tension.
Characterized by nervous tension or suspense.
Linguistics Enunciated with taut muscles, as the sound (ē) in keen.
Plural form of tent.
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.