Slang for a fabrication facility, a plant where semiconductors are made. The level of sophistication of a fab is usually reflected in two factors, the size of wafer it can process, with more evolved fabs using bigger wafers, e.g., 4-inch/10cm/100mm, 8-inch/20cm/200mm and 12-inch/30cm/300mm; and the size of the circuit lines it can etch, with finer lines being more evolved, e.g., 0.37 microns, .18 microns, 90 nanometers, 67 nanometers, 45 nanometers. Current costs for a high-end fab, e.g., 300mm at 90nm are of the order of $1 billion.