Difference between a 'condo' and a 'condominium' [closed]

The original word was condominium. In popular and casual use it was abbreviated to condo. There is no difference in meaning.

The same process of truncating abbreviation happened to photograph/photo, examination/exam, memorandum/memo and many other words. Please note that these truncated abbreviations are not the same as acronyms (PC = Personal Computer) or texting abbreviations (IMHO, In My Humble Opinion)

There is no difference except that "condominium" belongs to the current register whereas "condo" is informal (colloquial, in other words). Both words are used synonymously in certain articles (ref.).