You may have heard about business clusters which economists can use to identify areas or regions with a concentration of knowledge, skill, or production in a particular field or specialty. Identifying clusters is one way in which the initial stages of regional development can be organized. There is no standardized methodology for establishing what a cluster is, how it benefits a region, and whether some types of clusters are more beneficial than others but this certainly doesn't mean the concept can't be helpful to any discussion of development.
A publication released in January of this year called "Unlocking Rural Competitiveness: The Role of Regional Clusters" offers a good introduction to clusters, how they can be identified, and how rural regions can use this concept to inform their development efforts. There is a full report version and a shorter tri-fold brochure released by the Purdue Center for Regional Development, both focus on the work done at Purdue to define clusters and explain their applicability to rural development. There is a website that has all the information you need to get started including PDFs of the report by section, access to the data that was utilized, and links to more information on clusters.
If you previously had not heard about clusters, or found the concept too technical or intimidating, then this report might be a good place to start.