The words tracked, tract sound the same but have different meanings and spellings. Why do tracked, tract sound the same even though they are completely different words?
The answer is simple: tracked, tract are homophones of the English language.
Simple past tense and past participle of track.
An expanse of land or water.
A specified or limited area of land: developing a 30-acre tract.
Anatomy A system of organs and tissues that together perform a specialized function: the alimentary tract.
Anatomy A bundle of nerve fibers having a common origin, termination, and function.
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").