The words ware, wear, weir, where sound the same but have different meanings and spellings. Why do ware, wear, weir, where sound the same even though they are completely different words?
The answer is simple: ware, wear, weir, where are homophones of the English language.
An article of commerce.
An immaterial asset or benefit, such as a service or personal accomplishment, regarded as an article of commerce.
Archaic To beware of.
Obsolete Watchful; wary.
To carry or have on the person as covering, adornment, or protection: wearing a jacket; must wear a seat belt.
To carry or have habitually on the person, especially as an aid: wears glasses.
To display in one's appearance: always wears a smile.
To bear, carry, or maintain in a particular manner: wears her hair long.
A fence or wattle placed in a stream to catch or retain fish.
A dam placed across a river or canal to raise or divert the water, as for a millrace, or to regulate or measure the flow.
At or in what place: Where is the telephone?
In what situation or position: Where would we be without your help?
From what place or source: Where did you get this idea?
To what place; toward what end: Where is this argument leading?
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").