This document discusses basics of sheet metal and usage of NX sheet metal tools. Sheet metal involves thin metal plates and sheets that are formed using processes like bending, stretching, and shearing. Common items made from sheet metal include appliances, car bodies, and aircraft panels. The document then lists and describes various tools in NX for modeling sheet metal parts, including tabs, flanges, hems, bends, punches, and other features. It provides details on how each tool is used to create or modify the sheet metal model.