ord

Ord is a term used in several disciplines, typically as an abbreviation for order or ordinal. In mathematics, ord may denote the concept of order in various structures. The order of a finite group G is the number of elements in G, often written |G|. For an element a in a group, the order ord(a) is the smallest positive integer n such that a^n equals the identity element. The notion of order extends to other algebraic structures as well. In set theory and related areas, ordinal numbers describe positions in a well-ordered sequence; ordinals are well-ordered by definition, and the class of all ordinals is sometimes denoted Ord in mathematical texts.

In computing, ord is a standard function in several programming languages. In Python, ord(c) returns the Unicode code point, an integer, of the single-character string c; the inverse function is chr(i). Many other languages provide a similar operation, often as a method on a character or string type (for example, strings may expose an ord or code point function). These functions are used to convert characters to their numeric encoding for processing, storage, or comparison.

Outside mathematics and computing, ord can appear as an acronym or identifier in various contexts. For example, ORD is the IATA airport code for Chicago O’Hare International Airport. In general usage, ord is sometimes written as an abbreviation for ordinal or order in technical writing.

Overall, ord functions as a versatile shorthand in both theoretical and practical domains, most commonly linked to the ideas of order, ordinal numbers, or character encoding.