序列 (xù liè) is a noun meaning 'sequence' or 'ordered series'—a set of items arranged in a specific, logical, or chronological order. The first character 序 (xù) means 'order', 'precedence', or 'introduction', suggesting structure and position; the second character 列 (liè) means 'row', 'line', or 'list', emphasizing arrangement and enumeration. Together, they convey the idea of elements placed one after another according to a rule, pattern, or time-based progression.

This word is common in academic, technical, and everyday contexts—such as mathematics (number sequences), biology (DNA sequences), computing (data sequences), and daily life (e.g., the sequence of steps in a recipe or the order of speakers at an event). It implies intentionality and logic in ordering, not just random succession. While often formal, it’s also used in neutral registers and appears frequently in written Chinese more than in casual speech.