Terms are the numbers of a sequence. For example, the numbers 4 and 7.5 are terms in the set R (the real numbers). In the sequence a1, a2,…, ai,…,an the term an can represent an arbitrary term in the sequence, where n gives its position. Alternatively, if the sequence is finite, an can represent the last term of the sequence, and the index n gives the number of terms in the sequence.