“Broad Spectrum CBD” is Hemp Oil, extracted from hemp plants and then isolated from other molecules also present in the plant (like sugars, water, THC, etc.). “Nano” simply describes the size of the hemp oil molecules.
Imagine a gallon of water; it’s possible to drink the gallon all at once, but it’s easier to drink it a glass at a time over an hour. Your body can’t absorb a gallon of water all at once, it can only absorb one liter an hour. If you drink the entire gallon, your body will only absorb a liter of the water over the course of an hour. The remaining 3 liters of water doesn’t get used, instead it passes through you. Think of the gallon of water as regular CBD and the glass of water as Broad Spectrum Nano-CBD.
Nano-size makes it easier for your body to absorb, and faster absorption means faster results.