In a bipolar junction transistor (BJT):
$I_E$ (emitter current) is the total current leaving the emitter.
$I_C$ (collector current) and $I_B$ (base current) are components of $I_E$
According to Kirchhoff's Current Law (KCL): $I_E = I_C + I_B$.
Typically, $I_B$ is much smaller than $I_C$, making $I_E$ approximately equal to $I_C$.