The words lama, llama sound the same but have different meanings and spellings. Why do lama, llama sound the same even though they are completely different words?
The answer is simple: lama, llama are homophones of the English language.
A Buddhist monk of Tibet or Mongolia.
A domesticated South American ruminant mammal (Lama glama) related to the camel, raised for its soft, fleecy wool and used as a beast of burden.
Any of various other mammals of the genus Lama, such as the alpaca and guanaca.
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").