What is the difference between original and compatible batteries?

What is the difference between original and compatible batteries?

Original batteries are manufactured by companies like IBM and Sony and also by an Original Equipment Manufacturer (OEM), who manufacture under license from companies like IBM and Sony. Compatible batteries are solely made by 3rd party manufacturers. These products are not produced under license and cannot be labelled or branded as Sony, IBM, Toshiba etc. The physical attributes are the same between the two types of batteries, but the labeling will be different.