well you have the mod and you screw on the atomizer correct? meaning you have several pieces of metal and connections between the atomizer and the battery inside the tube.
a hybrid removes these connection and turns the atomizer bottom into the topcap for the mod, removing all the extra connections and making the battery more efficient
if you use the Kayfun model 3.1ES it has a special plate you can put on the bottom then unscrew the top cap from the semovar and screw the atty on instead.
the result is a more finished streamline look with less connections in the way. looks very clean and sharp.
the idea for the semovar hybrid connector came from stuff like this,
http://www.310vapers.com/catalog/product/view/id/223/s/macaveli-350-v2-grey/category/7/
this a true hybrid, it is one solid tube and you cannot unscrew the atomizer you build the atty pop in a battery and go.