Wattage is a unit of power. More wattage means more power consumed which results in a higher energy bill.
The single worst way to decide what kind of luminaire to buy for a modern buyer is wattage. In the past, wattage scaled against output for most sources. With LED lights, the wattage is a great comparison tool for how well the product converts electrical energy into light – but that is it.
When looking at buying a light fixture, it is recommended that you wait until you are at the point of product comparison before looking at the wattage. Once you have balanced the other factors, buying a light with the lowest wattage that meets your requirements is ideal because this will lower your electrical bill the most.