Arithmetic Sequence: A sequence in which the difference between any two consecutive terms is a constant.

Arithmetic series: For an arithmetic sequence, the indicated sum of the terms.

Common difference The different between two consecutive terms of an arithmetic sequence.

Common ratio: The ratio between two consecutive terms in a geometric sequence.

Converge: For an infinite geometric series to converge it is necessary that |r|<1, where r is the common ration of the sequence in question.

Diverge: Given an infinite geometric series, this diverges if |r|³1, where r is the common ratio of the sequence in question.

Geometric Sequence: A series of numbers for which each consecutive number is the previous one times a constant known as common ratio.

Geometric series: Given the terms of a geometric series; the geometric series is the indicated sum of the terms.