Drawing pencils are characterized by being divided into 13 grades according to the hardness of the refill, which are distinguished by English letters H and B. ..
In sketch learning, commonly used pencils have only five grades (H2 to B2 * * *). H-class pencils are light in color and easy to modify, which is suitable for sketching. Class B pencils can draw dark objects to save drawing time. Drawing pencils are suitable for beginners.
But my advice is that beginners should not spend too much energy on the choice of pencils, because the change of sketch is not based on the difference between the hardness of pencils, but on the weight of hands and the overlap of lines.