A point given by x-, y- and z-coordinates in a cartesian coordinate system is named node in finite element analysis.
In a 2D or 2.5D system a node is part of a beam element or a triangle element.
In a 3D system a node is part of a tetraeder, hexaeder or a prism element.
The analysis in a FEM system is normally done from one node to his neighboring nodes.
Calculated results will be assigned to the given node.