A Capsule is a container that holds other items. They can be used to organize items and operate on them in bulk. Any item, except for a Capsule, can be placed within a Capsule.
INGRESS MUFG CAPSULE:
The MUFG Capsule is a sponsored item that bears the name of Mitsubishi UFJ Financial Group, Inc. It has identical properties to a standard Capsule, but like its investment-bank patron, it can pay interest in the form of duplicated items.