Updated: 09/12/2023 by Computer Hope

X may refer to any of the following:

White X

1. An x is generally used to represent a generic variable. For example, Computer Hope and other companies write Microsoft Windows 3.x. The "x" can be replaced with any valid digit. For instance, it may represent the "1" in Windows 3.1 or the "11" in Windows 3.11.

2. An X refers to the transfer speed with a computer CD (compact disc) drive. For example, the original 1X CD-ROM had a speed of 153,600 Bps, and a 24X CD-ROM had a Bps of 3,686,400 or 153,600 x 24. The higher the number, the faster data will be read from the CD drive. See the CD-ROM (compact disc read-only memory) definition for further information about transfer speeds.

3. In mathematics, an x may represent a times sign. For example, 4 x 4 = 16. The times sign may also be an interpunct (·) or an asterisk (*). See our multiply page for further information.

4. When shown in the window's top-right corner, the X is a button to close a window.

5. X is a service found on some IRC (Internet Relay Chat) networks that allows users to manage the chat rooms, called channels, that they can view.

6. Abbreviation for X Window System. See the x command page for further information about this command.

7. X is a keyboard key used with the keyboard shortcuts Alt+X, Command+X, and Ctrl+X.

8. In chat, 'x' or 'X' represents a kiss. For example, "xoxo" is a kiss, hug, kiss, and hug.

9. With regular expressions, "x" is a regular expression flag that allows spaces and comments.

10. With Microsoft Excel and other spreadsheet programs, "X" is the twenty-fourth column of a spreadsheet. To reference the first cell in the column, you'd use "X1."

11. X.com is a domain name owned by Elon Musk that became the name of his new company after purchasing and renaming Twitter to "X" on July 24, 2023.

12. Formerly Google X, X is a subsidiary of the Alphabet conglomerate. See the X company page for further information.

13. In the phonetic alphabet, "X" is often pronounced as "x-ray."

14. As a Roman numeral, "X" is 10.

15. X is the twenty-fourth letter of the English alphabet. The letter "X" comes after "W" and is followed by the letter "Y." To create a capitalized "X," press Shift and X at the same time.

On a U.S. QWERTY keyboard, the "X" key is on the bottom row, to the right of "Z" and left of the "C" key. See our keyboard page for a visual example of all keyboard keys.


If the "X" key is not working on the keyboard, see: Some keys on my computer keyboard aren't working.


In ASCII (American Standard Code for Information Interchange), the uppercase "X" is "088" in decimal (01011000 in binary). The lowercase "x" is "120" in decimal (01111000 in binary).


Doing the Alt code Alt+88 creates a capital "X," and Alt+120 creates a lowercase "x" character.


The number 9 on a phone keypad creates an "X" on a US phone.

CD terms, Chat terms, Computer abbreviations, Letter, x86