Here is a brief glossary of definitions for network analysis (cf. Sporns et al. Trends in Cognitive Sciences, 2004; Kaiser, Phil. Trans. R. Soc, 2007 - PDF's available on my website).
Component: A component is a set of nodes, for which every pair of nodes is joined by at least one path.
Connectedness: A connected graph has only one component. A disconnected graph has at least two components.…