In the US, flours are categorized by how much protein they contain, which directly affects the gluten formation in whatever is being made.
In Italy and other parts of Europe, flours are categorized based on how finely the flour has been ground. Coarsely ground "2" flour is at one end of the spectrum with powder-fine "00" at the other end. The "00" flour makes an extremely supple pasta dough, smooth as silk, easy to roll, and very tender to the bite when cooked.
WHAT IS "00" FLOUR?