terminology - What's the difference between "extent of reaction" and "position of equilibrium"?

My chemistry textbook defines the terms in question as follows:

Extent of reaction: the relative amounts of products compared with reactants. The extent of reaction is indicated by the value of the equilibrium constant.

Position of equilibrium: the relative amounts of products and reactants at equilibrium. The position of equilibrium varies depending on the extent of the reaction.

I don't understand the difference between these two concepts and would appreciate it if someone could explain both how they are different and how they are linked/influence each other.

Thanks.