In a series circuit, all components are connected end to end to form a single path for current.
Resistor in series:
When resistors are connected in series, total voltage across all resistors is equal to the sum of the voltages across each resistor.
V = V1 + V2 + V3
V ∝ R
Req = R1 + R2 + ……… +Rn
In a parallel circuit, all components are connected in such a way such that it divides current in multiple paths.
Resistor in parallel:
When resistors are connected in parallel, the voltage across each resistor is the same, but current is different.
In a parallel resistor network, the circuit current can take more than one path as there are multiple paths for flow of current.
Hence, parallel circuits are also called current dividers.