Clusters, which are groups of companies, suppliers, research institutions and public authorities, have proved to be successful. Companies in well developed clusters grow faster and are more innovative than companies which are not part of dynamic clusters. Several types of cluster exist and they can develop in many different ways. In general, the USA is relatively advanced when it comes to the development of strong clusters. In more recent years, there has been a greater focus on the value of clusters and many countries now support and are attempting to establish clusters.