The words tooter, tutor sound the same but have different meanings and spellings. Why do tooter, tutor sound the same even though they are completely different words?
The answer is simple: tooter, tutor are homophones of the English language.
A person or device which toots; a person who plays upon a pipe or horn.
A private instructor.
One that gives additional, special, or remedial instruction.
A teacher or teaching assistant in some universities and colleges having a rank lower than that of an instructor.
A graduate, usually a fellow, responsible for the supervision of an undergraduate at some British universities.
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").