Life in these modern times thrives off of structure and networking. Even the most basic of colonies are interlocked and interdependent on one another. Simply having a single building to cater to the various needs and responsibilities of a modern colony is not possible. Should one view the buildings of a colony as the pieces of an anatomy, the Citadel would most certainly be the heart. The Citadel is a centralized building that provides the means and the networking capabilities to support other, more focused and role-specific structures in a colony.
Upon constructing and upgrading a Citadel, new building options will become available to meet the needs of the colony. The Citadel itself during these upgrades, transforms in many ways. One is the size, as the Citadel will begin to house new technologies and personnel. In addition, supplementary data nodes are installed with each upgrade to allow for more specific and organized transmission of orders and data to the tertiary buildings of the colony.