**3.1 Levels of units**

The sequence builds up from a foundation towards higher levels of organisation:


This hierarchy has been carefully developed and it is argued (although not definitively) that each of these levels have particular properties which separate it from those lying at other levels in the hierarchy.

At each of these levels, the social unit focused on has 'internal' and 'external' features: the elements that make it up and its relationships to other units within which it is contextualized. In a network approach, which is a major way of investigating the latter issue, relations between nodes are studied, not characteristics of nodes themselves. Network linkages within any type of social entity (e.g. between individuals but also between organisations) are possible. This interest in linkages can be taken to **follow** approaches looking at characteristics of social entities (on the grounds that you need to know something about x and about y before you examine their relationship). However, often network analysis is seen as the study of relationships amongst people rather than relations amongst any type of social unit as it is depicted in this chapter.

It is important to note that the various levels do NOT neatly (at least not necessarily) nest within each other in a linked-up hierarchy. Social structures at various levels cross-cut and interweave and may (or may not) have any connection with others operating at different scales or with different trajectories.
