The UL-94 Vertical Burning Flammability Test (UL-94V) is used to measure flammability characteristics of plastic materials. The results of the test allow for plastic materials to be separated into classification categories. These categories will be discussed and related to fire phenomena. Simulations of the test have allowed for the development of general flame height and heat flux correlations. We believe these are independent of the actual solid fuels. In addition, the heat flux from the ignition burner, a specified premixed flame, has been measured. These data provide the basis for assessing fire behavior of materials using their fire properties such as heat of combustion, heat of gasification, ignition temperature, and thermal properties. Criteria for ignition, sustained burning, and flame spread are determined. These outcomes are then related to the UL-94V classification categories. An analysis of melting is also considered in order to assess the flaming drip aspect of the test.