Electroplating is pretty and yields a nice finish that is acceptable in items that are exposed to the elements when given additional protection, such as painting, etc. Hot dipped is a stand alone protection that is almost universally used where exposure is constant/critical and other methods of protection are not viable.
If you want maximum protection, hot dipped galvinizing is the 'hot' setup, short of SS.
The above answers are correct. My comment is that the galvanize process is most suited for mass production, where continuous sheet stock is coated at 100's of feet per minute or fasteners are bulk processed by the ton. Electroplated zinc is used for custom parts & products requiring machining and fabrication. Also, zinc plating can be done post-welding and when cutting & drilling leave too many exposed edges on galvanized sheet.
