A pole is a set of edges that merge into a single vertex. Avoiding poles with six or more edges on a curved surfaces is something that you should incorporate into your modeling workflow.
It is best practice for you to avoid poles when modeling. Using poles can interrupt a customer’s workflow when they subdivide. When a customer subdivides a model with poles, the result will be a “star” pattern in the topology. This can make modifying and editing your model difficult for customers.
When a customer renders a subdivided model the includes poles, the renderer interprets the pole as a sharp point that causes a break in highlights and textures. This may only be evident at certain angles, but customers reasonably expect models to render without errors regardless of the angle. Avoiding poles is another way to make your model more desirable to customers as it allows them more freedom in using and manipulating models they purchase.