A point where two or more edges point is called a vertex. In simpler words it is the corners of the geometrical shape.
For example:
Consider the above rectangle: It has 4 vertices (plural of vertex). As it has 4 corners and at each corner two edges meet.
Similarly
- Cubes and cuboids have 8 vertices
- Cones have 1 vertex
- Cylinders have no vertex
- Spheres have no vertex (the surface is a curve)