# class (category)

a set of things that do not differ in type

- Computed level: L5 (depth in the emergence graph, not abstraction)
- Status: review  ·  Domain: taxonomy  ·  Arena: class

## Emergence
**Emerges from:** [sets](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-sets.grouped), [type](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-type.category), [difference](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-difference.relation)

**Through:** the set collects things while type and difference determine sameness, allowing a class to emerge

**Novel properties:**
- categorical unity
- internal indifference
- type-based grouping

## Examples
- The Boeing 747 fleet shares a type-certified airframe design across all units produced from 1969 to 2023. *(engineering)*
- Homo sapiens sapiens individuals are grouped as a biological class based on shared genomic markers and reproductive compatibility. *(biology)*
- All instances of Bitcoin version 0.1.5 belong to the same software class, released on February 11, 2009. *(computing)*

---
*Canonical: https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-class.category*  
*Structured data: https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-class.category.json*  
*Every definition provably resolves to space, time, energy and pattern.*