Explanation:

Different types of Agroforestry systems exist in different parts of the world. These systems are highly diverse and complex in character and functions.
1. Structural Basis: Consider the composition of the components; specially refer including spatial admixture of the woody component, vertical stratification or the component mix and temporal arrangement of different components.
2. Functional Basis: This is based on the major function or role of the system; mainly of the woody components (This can be productive or protective).
3. Socio-economic Basis: Consider the level of inputs or management (low input, high input) or intensity/scale or management and commercial goals.
4. Ecological Basis: Take into account the environmental conditions on the assumption that certain types of systems can be more appropriate for certain ecological conditions.