Cropping a photo is usually seen as a creative choice, but in the real world it’s not always quite that simple. Very often, you need to produce an image to fit a specific display size or aspect ratio, and you won’t know what that is until the time comes.
Frames
Another word for borders applied digitally to a photo, either as a compositional aid to enclose the picture, for example a black keyline, to simulate the look of negatives or prints, or (in the worst case) to produce a pretend wood or metal frame.