Complexity science, also called complex systems science,
studies how a large collection of components - locally
interacting with each other at the small scales - can
spontaneously self-organize to exhibit non-trivial global
structures and behaviors at larger scales, often without
external intervention, central authorities or leaders.
The properties of the collection may not be understood or
predicted from the full knowledge of its constituents alone.
Such a collection is called a complex system and it requires
new mathematical frameworks and scientific methodologies
for its investigation.