A vertex is a point where several lines or segments converge or join. In geometry, it is the point of intersection of two or more lines forming an angle.
In the context of polygons, such as triangles or quadrilaterals, vertices are the points where the sides meet.
Furthermore, in the realm of networks or diagrams, a vertex can represent a node or an entity connected to others. Vertex are fundamental for understanding the structure and interconnections in various geometric or graphical systems.