What data does the Google drive app contain in an android smartphone?
What does does this app exactly contain


The app's files and settings, plus the files that you have made available for offline use.


  and what I may lose on clearing this app's data?


Nothing. Only the data that were on the phone. Files that were uploaded to Google Drive wont be affected. They can only be deleted if you delete them from within the app. The app will return to the state it was in the first time you use it on the phone.