The words tool, tule, tulle sound the same but have different meanings and spellings. Why do tool, tule, tulle sound the same even though they are completely different words?
The answer is simple: tool, tule, tulle are homophones of the English language.
A bookbinder's hand stamp.
A device, such as a saw, used to perform or facilitate manual or mechanical work.
A machine, such as a lathe, used to cut and shape machine parts or other objects.
The cutting part of such a machine.
Any of several bulrushes of the genus Scirpus, growing in marshy lowlands of the southwest United States.
Northern California Marshy or swampy land. Also called regionally tule land.
A fine, often starched net of silk, rayon, or nylon, used especially for veils, tutus, or gowns.
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").