The words steer, stere sound the same but have different meanings and spellings. Why do steer, stere sound the same even though they are completely different words?
The answer is simple: steer, stere are homophones of the English language.
To guide by means of a device such as a rudder, paddle, or wheel.
To direct the course of. See Synonyms at conduct.
To maneuver (a person) into a place or course of action. See Synonyms at guide.
To guide a vessel or vehicle.
A unit of volume equal to one cubic meter.
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.