The words bread, bred sound the same but have different meanings and spellings. Why do bread, bred sound the same even though they are completely different words?
The answer is simple: bread, bred are homophones of the English language.
A staple food made from flour or meal mixed with other dry and liquid ingredients, usually combined with a leavening agent, and kneaded, shaped into loaves, and baked.
Food in general, regarded as necessary for sustaining life: "If bread is the first necessity of life, recreation is a close second” ( Edward Bellamy).
Something that nourishes; sustenance: "My bread shall be the anguish of my mind” ( Edmund Spenser).
Means of support; livelihood: earn one's bread.
Past tense and past participle of breed.
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.