x
Symbol  Format  Data 

x  Code Point 
U+0078 
TeX 
x 

SVG 
The Latin small letter x is used to represent a variable or coefficient. In algebra, x is often used to represent an unknown value. The symbol x is also used to represent the horizontal dimension in the 2D cartesian coordinate system.
The capital Latin letter X is used to represent a random variable in statistics
A variable is a symbol that represents an unknown or indeterminant quantity. Variables can represent numbers, vectors, or other mathematical objects, depending on the context.