how are regional boundaries different from state boundaries?

Answer 1

In some cases a region can contain several states, such as New England. Although each state is different, they tend to hold attitudes and heritage that separates them from the rest of the country.

In some cases a state can be divided into different economic regions. Illinois is one. The southern most 16 counties are called "Southern Illinois" and is different than the rest of the state in that it is high rural (No cities at all), depends economically on a mixture of agriculture, mining and small businesses.

Answer 2

I wonder which country or part of the world you are thinking about?

In federal countries such as India, Brazil, and Nigeria, there is some tendency to think of regions that each comprise a group of states. Sometimes these 'regions' have official definitions for planning purposes and statistical measurements; rarely do they have any substantive political existence or democratic structures. States on the other hand are poitically important entities with their own elected structures.

At another level, economists can talk about 'regions' of the world such as "Asia-Pacific" or "Western Europe" comprising a group of 'states'.... ie countries, for most countries are not federal and the word 'state' is used interchangeably with 'country'.