Definition:Absolutely Convergent Series/Complex Numbers

Definition
Let $S = \ds \sum_{n \mathop = 1}^\infty a_n$ be a series in the complex number field $\C$.

Then $S$ is absolutely convergent :
 * $\ds \sum_{n \mathop = 1}^\infty \cmod {a_n}$ is convergent

where $\cmod {a_n}$ denotes the complex modulus of $a_n$.

Also see

 * Definition:Conditionally Convergent Series, the antithesis of absolutely convergent series.