There are two ways arranging resistors, series circuits and parallel circuits.
In a series circuit, the resistors are arranged in a chain, so the current has only one path to take and is the same through each resistor. The total resistance is equal to the sum of the resistances:
In a parallel circuit the resistors are arranged with their heads connected together, and their tails connected together.
The current breaks up and flow among each different branch through the resistors and re-combining when the branches meet again. The voltage through each parallel resistor is the same. The total resistance is reduced and is given by the relationship: