Two end nodes and zero or more internal nodes, or vertices, define a line. A node or vertex is like a point, but it only serves to define the line and provide shape in order to obtain a better approximation of the actual feature. The straight parts of a line between two consecutive vertices or end nodes are called line segments. Many GISs store a line as a sequence of coordinates of its end nodes and vertices, assuming that all its segments are straight.
Vertex
Explain and be able to apply basic vector and raster spatial data structures including selecting a suitable data structure for geographic phenomena (level 1, 2 and 3).