Kit Single
What are single lens kit and a twin lens kit?
What Thet used?
A kit with one lens is the body of the camera + battery + charger + Neckstrap + instructions + software + lens. Usually the lens is something like a 18-55mm zoom. Such an objective will cover 80% of the needs of most people. A two-lens kit is all something like the above plus a 55-200mm zoom. The additional lens is used for things like sports and wildlife photography. You can start with the kit lens and see if you really need for additional lenses. That would save some money up front. Or, if you think you want the extra zoom range anyway, get the two kit lenses. Buying a kit with two lenses is a bit cheaper than buying everything separately. In any way, the only thing you need to add a memory card. Some stores throw in free.
