Series Circuit: R1+R2+R3+...=Rt V1+V2+V3+...=Vt All current is equal(Kirchhoffs Law) These circuits only allow for current to travel in one path. Parallel Circuit: 1/Rt=1/R1+1/R2+1/R3+... I1+I2+I3+...=It All voltage is equal (Kirchhoffs Law) These circuits allow for current to flow in multiple directions.