Antibacterial soaps contain Triclosan, a water soluble organic compound that has shown to have anti bacterial properties.
Regular soaps are just a mixture of fatty acids, oils, or detergents.
All natural soaps usually boast that they are made of "natural ingredients" and do not contain harsh detergents or synthetic ingredients like perfume.
Most often, antibacterial soaps are not necessary to kill germs , as regular soap has been shown to kill just as many germs with thorough washing.
Antibacterial soaps can be bad for the environment. Triclosan can not be "rid" during water treatment filtration processes, so it usually ends up in local streams where it can have devastating effects on aquatic life.