User Acceptance Testing

Reporting malfunctions

When reporting a (perceived) malfunction, useful are

URL
any sort of relevant metadata (specific parameter, previous page, state of the app, etc)
screenshot, if it is a UI problem
(sometimes) screenshot of the console logs

Bugs vs new Features

Bugs are malfunctions. The received output is not the one that was expected.
Features are functionalities that one wishes were present/implemented but were not implemented yet.