Complex circuits may have some resistors connected in series, and some connected in parallel. For example, the following combination of resistors shows two resistors connected in series ...

Two lamps connected in series with ... same throughout a circuit and voltages add up to the supply voltage. Components that are connected on separate loops are connected in parallel.

Software simulations which are based on complex algorithms will help to get the accurate results. To make my point clear consider simple circuit consisting of two parallel resistors and an input ...