Referencing a given data structure is done by assigning our data structures to variables using the assignment operator, =.
Variables are references to values, like data structures, and the type of the variable is determined by the type of the value that is assigned to the
variable.
Variables do not have a set data type; they are simply a name that refers to a value. The data type of a variable is determined by the type of the value that is currently assigned to the variable.
In Python, variables are references to objects, which means that when you create a variable and assign a value to it, the variable does not store the value directly, it instead stores a reference to the object that contains the value.