An order is a way of sorting entries, also called elements, in a list. The mathematical concept of linear order is closely related.

• Chronological order — listing by time, often earliest to latest.
• Lexicographical order (alphabetical order or dictionary order) — listing based on the first letter of the entry. Apple, Banana, etc.
• Most important to least — listing based on the most relevant entry to the least.

Many sorting algorithms exist, and much study has been done of their properties, including efficiency of time and storage.