Voltage Divider

It's a circuit where you have resistors in series and the voltage gets distributed among the resistors

$V_{j} = i R_{j}$
$V_{j} = \frac{V_{s} R_{j}}{R_{e q}} = \frac{R_{j}}{R_{e q}} V_{s}$ Where $R_{e q}$ is the total resistance
Basically, the voltage it takes is proportional to the fraction of the total resistance

Current Divider

It's the same thing
except in parallel instead of in series
and the formula is $I_{x} = \frac{R_{T}}{R_{x} + R_{T}} I_{s}$ , where $R_{T}$ is the sum of the resistances in all other branches