The term “criticality” has several meanings depending on the context:
1. **General Definition**: It refers to the quality or state of being critical, which can imply importance or urgency in a situation or context.
2. **Physics/Nuclear Engineering**: Criticality describes the condition in which a nuclear reactor is sustained at a certain level of fission reaction. A system is considered “critical” when it can maintain a steady rate of nuclear fission without increasing or decreasing over time.
3. **Systems Theory**: In this context, criticality can refer to a phase transition within complex systems, where small changes can lead to significant effects or a shift in behavior.
In summary, criticality generally denotes a crucial or decisive state, particularly in technical or scientific contexts.
