Capital x stands for
Use Roman numerals to represent 10.
The legendary Japanese visual orchestra X JAPAN is called X for short.
In XL, it means "plus" and "extra". English extra pronunciation
X Window System is a free graphical window interface developed by MIT.
x chromosome
X file
The lowercase x stands for
In algebra, the variable x is usually used to represent the unknown quantity; This usage can be traced back to Arabic.
In analytic geometry, it is usually used to represent the horizontal coordinate axis.
Other usage
When writing, it is used to cover up invisible words, such as confidential words or dirty words.