几个电路组件的两端分别连接于两个节点，此种连接方式称为并联。连接点称为节点。以并联方式连接的电路称为并联电路。从并联电路的电源给出的电流等于通过每个组件的电流的代数和，给出的电压等于每个组件两端的电压。

几个电路组件沿着单一路径互相连接，每个节点最多只连接两个组件，此种连接方式称为串联。以串联方式连接的电路称为串联电路。从串联电路的电源给出的电流等于通过每个组件的电流，给出的电压等于每个组件两端的电压的代数和。

串联和并联是两种常见的基本连接方式。电路组件也可以以其它种方式连接在一起。例如，星形电路或三角形电路。

Components of an electrical circuit or electronic circuit can be connected in many different ways. The two simplest of these are called series and parallel and occur frequently. Components connected in series are connected along a single path, so the same current flows through all of the components. Components connected in parallel are connected so the same voltage is applied to each component.