This document discusses sequences and series in calculus. It defines sequences as ordered lists generated by a function with domain of natural numbers. Sequences can be finite or infinite. A sequence converges if its terms get closer to a number, and diverges otherwise. A series is the sum of terms in a sequence. If the number of terms is finite, it is a finite series, and infinite otherwise. A series converges if the sum converges, and diverges otherwise. The document introduces tests for determining convergence of sequences and series, including the nth term test for divergence. It provides examples to illustrate these concepts.