The document discusses different types of business-to-business (B2B) electronic marketplaces called e-Hubs. It describes MRO Hubs which concentrate on regularly purchased maintenance, repair, and operating goods. Catalog Hubs are similar but focused on specific manufacturing inputs. Yield Managers specialize in one-time sourcing when prices or demand fluctuate for hard to acquire assets. Exchanges help manufacturers exchange parts to manage production variability.