### Definitions

The following concepts, categories, units, etc. require precise definition or description:

- Regions: IMAGE 2.4 world regions and their countries
- Animals: animal categories and animal products used in IMAGE 2.4
- Crops: classification of crops in IMAGE 2.4
- Land Cover & Vegetation: land cover and vegetation types in IMAGE 2.4
- Timber: forest stages, forestry types and wood product types
- Compounds: elements and chemical compounds
- Acronyms: acronyms used throughout the documentation and their meaning
- Measures & Units: used abbreviations and their meaning