I would like to briefly explain the difference between Bugs, Improvement/Adjustment and New Features as I have come to understand from a development POV
These are coding errors that produce unexpected behaviours that were not anticipated by the developer. It can be either visual bugs (user completes given function but something about the ui looks wrong. Often its an error resulting from responsiveness). E.g.,
A large button that does not fit well in smaller screen resolutions
or functional bugs(error in computation or logic that leads the app to not work as intended or produce flawed results) E.g.,