Region is a geographic term used in many ways in the different types of geography. In general, a region is a medium-scale area of land or water. It is smaller than the whole area of something (which could be, for example, the world, a nation, a mountain range, and so on). A climate zone is one kind of region.
A region is larger than a specific location. It may be seen as a collection of smaller things (as in "the New England states") or as one part of a larger whole (as in "the New England region of the United States"). In some countries a region is a unit of local government.