The words emerging, immerging sound the same but have different meanings and spellings. Why do emerging, immerging sound the same even though they are completely different words?
The answer is simple: emerging, immerging are homophones of the English language.
Newly formed or just coming into prominence; emergent: emerging markets; the emerging states of Africa.
To submerge or disappear in or as if in a liquid.
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").