I use Redmi Note 3 with Android 6.0.1. Out of 10 GB internal storage, 4.5 GB is occupied only by apps. I see that app data and app cache eat up a lot of free space. I safely delete app cache data.But since that's not enough so I want to delete my app data also. But all my files in my phone are important to me so I want to be sure that deleting my apps data won't delete my personal files. Some of the apps whose app data I intend to delete are Google play services, Google drive, Mi Browser and Google chrome. I am not sure what files does this 'app data' contain and I don't know if there's any method to know that.
Clearing an app data DO delete files from your phone. Becuase those files are associated directly with the apps that you are deleting. Any other files which are not AUTOMATICALLY created by the app being deleted will not be deleted when you clear an app's data.
So, go ahead and feel free to delete an app's data. But be careful deleting an app's data actually resets that app into a freshly installed app state. And if you delete the Google app's data chances are that you might lose some bookmarks, history or any preferences you have set previously.