The words baht, bot sound the same but have different meanings and spellings. Why do baht, bot sound the same even though they are completely different words?
The answer is simple: baht, bot are homophones of the English language.
See Table at currency.
The parasitic larva of a botfly.
A disease of mammals, especially cattle and horses, caused by infestation of the stomach or intestines with botfly larvae.
A software program that imitates the behavior of a human, as by querying search engines or participating in chatroom or IRC discussions.
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").