These factors can vary significantly among the different types of gates. Always determine which latch and hinges are to be used in advance. Vinyl gates vary significantly. That is the actual gate width. Again, it depends entirely on the hardware to be used.
Ornamental gates can vary also.
The sizes in our catalogs are opening sizes. The first time installer would be wise to set the hinge side post of the gate first. Hang the gate and hardware and then install the latch-side post last. You will be guaranteed of a perfect fit every time.