a) A sequence is an ordered list of numbers and a series is the sum of a list of number. b) A convergent series is a series where the sum of all of its terms is finite. A divergent series is a series where the sum of all of its terms is infinite or its $n$-th partial sum doesn't approach a finite number as $n→ \infty$.
Work Step by Step
a) Definition of sequence and series. b) Definition of convergent and divergent series.