The words bailer, bailor, baler sound the same but have different meanings and spellings. Why do bailer, bailor, baler sound the same even though they are completely different words?
The answer is simple: bailer, bailor, baler are homophones of the English language.
one who bails or lades.
a utensil, as a bucket or cup, used in bailing; a machine for bailing water out of a pit.
One who bails property to another.
A machine for creating bales, e.g., of hay or cotton.
A person who creates bales, either by operating or feeding such a machine, or by creating the bales by hand.
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").