The words torcher, torture sound the same but have different meanings and spellings. Why do torcher, torture sound the same even though they are completely different words?
The answer is simple: torcher, torture are homophones of the English language.
One who torches something
One who gives light with a torch, or as if with a torch.
A torch song
Infliction of severe physical pain as a means of punishment or coercion.
An instrument or a method for inflicting such pain.
Excruciating physical or mental pain; agony: the torture of waiting in suspense.
Something causing severe pain or anguish.
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.
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").