It’s a simple espresso recipe that says “18g of coffee beans, ground fine enough that 45g of liquid (espresso) come out in the cup in 30s from the start of the pump”. It tells you about the dose and the ratio, and the brew time is an indication since everything else is a variable depending on the beans, roast level, grinder, machine, temperature and humidity levels.
“dry” means unadulterated beans, since were talking about wetting them before grinding.