The idea behind transalation is to extract the text a user sees in your app from Interface Builder and other resources. All of those buttons names and text labels need to be translated, after all.
Each piece of text is placed in a simple text format called a .strings file.
Generally there are four steps involved in localizing with Translate any App:
Getting your resource files ready for localization.
Collecting all the texts used in the application in resource files.
Translating the resource files.
Integrating the resource files back in the application.