title_body: What's the difference between imperial pale ale and indian pale ale?
upvoted_answer: Most often, if you see IPA, it's an "India pale ale".
  
  "Imperial pale ale" is an informal, descriptive style (i.e., a strong pale ale), whereas "india pale ale" is a BJCP recognized style.  India pale ales are primarily understood as a hopped-up version of a pale ale, made to withstand long travels.  Beers with an "imperial" nomenclature (typically synonymous with "double") are brewed to be a stronger, higher ABV -- think double IPAs, imperial stouts, etc.