Varta also classify their car batteries into the technology types used;
Wet (Maintenance Free) - The classic type of car battery; these are ABS plastic cased batteries with lead plates and liquid elctrolyte around them.
AGM - Varta AGM Car Batteries are a heavier duty battery where the electrolyte is suspended within a glass matt material sandwiched between the plates. AGM batteries are traditionally used in higher end vehicles, but have recently been adpoted for many Start-Stop vehicles.
EFB - Varta EFB Car Batteries are a middle ground between wet and AGM batteries. EFB stands for 'Enhanced Flooded Battery' and are very heavy duty wet batteries that attempt to bring the benefits of AGM batteries but without the higher cost.