Think of it like a pipe with water flowing through it. The smaller the pipe, the more resistance there will be and less volume of water you can get down the pipe. Lower resistance is a bigger pipe you can put more water through.
With a small battery; if you try to pull more current through it by using a low-resistance atty or carto, you could blow the battery, and at the very least will shorten it's life. You need a bigger battery to pull more current through, just like you need a bigger pipe to pull more water through.
Wattage is the amount of power you produce by pushing that current down the given pipe. More wattage is more power which heats the coils hotter producing more, and warmer vapor.
With a small battery; if you try to pull more current through it by using a low-resistance atty or carto, you could blow the battery, and at the very least will shorten it's life. You need a bigger battery to pull more current through, just like you need a bigger pipe to pull more water through.
Wattage is the amount of power you produce by pushing that current down the given pipe. More wattage is more power which heats the coils hotter producing more, and warmer vapor.