In a series connection of resistors, the resistors are connected one after the other in a single path so that the same current flows through each resistor. The total resistance in a series circuit is the sum of the individual resistances, and the voltage is divided among the resistors.
In a parallel connection of resistors, the resistors are connected across each other so that the same voltage is applied to each resistor. The total resistance in a parallel circuit is less than the smallest individual resistance, and the current is divided among the resistors.