When you're working with resistors, it’s really important to know the difference between series and parallel setups. This is especially useful when you are learning about circuits.

Series Resistor Configuration:

• Total Resistance: In a series circuit, you find the total resistance by adding all the resistors together. For example, if you have resistors named $R_1$, $R_2$, and $R_3$, you add them like this:
  $R_{total} = R_1 + R_2 + R_3$

• Current Flow: The same amount of current flows through each resistor, so the total current is the same everywhere:
  $I_{total} = I_1 = I_2 = I_3$
  This makes series circuits pretty simple to understand.

• Voltage Drop: Each resistor can have different voltage drops. This depends on how strong each resistor is, which you can find using Ohm's Law:
  $V = IR$

Parallel Resistor Configuration:

• Total Resistance: In a parallel circuit, the total resistance is found in a different way. For the resistors $R_1$, $R_2$, and $R_3$, it looks like:
  $\frac{1}{R_{total}} = \frac{1}{R_1} + \frac{1}{R_2} + \frac{1}{R_3}$

• Current Distribution: The total current is shared among the resistors. So, for parallel circuits, you add the currents:
  $I_{total} = I_1 + I_2 + I_3$

• Voltage Consistency: The voltage across each resistor stays the same, which can make things easier when you do the math.

In simple terms, in a series setup, you add up the resistances and have one current flow through. In a parallel setup, you get a lower total resistance while the voltage stays the same across all resistors!