Nodes are places on the stem where leaves are attached and buds form. Roots often form at nodes of creeping plants and when cuttings are taken for propagation. Internodes are the segments of the stem between nodes.
The quality and amount of available light and temperature affect the length of the internode. The distance between nodes can be long or short. This distance reflects growing conditions. Plants grown under poor light conditions may be spindly, with very long, thin, and weak internodes.
Vinca growing in normal light	Vinca in dense shade.