The PowerEdge is a server line by Dell, following the naming convention for other Dell products: the Power Vault (data storage) and the Power Connect (data transfer & switches). Below is an overview of current and former servers within Dell’s PowerEdge product line. Different models are or were available as towers, 19-inch racks or blades. In the current naming scheme, towers are designated by T, racks by R, and blades by M (for modular). The 19″ rack-servers come in different physical heights expressed in rack units or U. Most modern servers are either 1U or 2U high while in the past the 4U was more common.