Question

Voltage and Ampere
I have a doubt .. Imagine i have a theoretical device that runs at 100 watts.. I can build it in two ways lets say

a) so that it runs with 100volts and 1 amp (by making sure it has 100 ohm resistance ) which i feel is a smart way than

b) make it run at 1 volt and 100 amps ( by making its resistance 1/100 ohm) which i know would inefficient and stupid and would require thick cables and could be lethal and dangerous and stuff.. but i need to understand the difference in the working