What is variable?
We explain what a variable is and the types of variable that exist. In addition, what are the uses of this value in various fields.
What is variable?
A variable refers, in the first instance, to things that are likely to be modified (to vary ) , to change depending on a given or undetermined reason.
The variable term refers to things of little stability , which in a short time can have strong alterations or that never acquire a constancy (very often this happens with the weather , or the mood of a person ).

Types of variables
Depending on how they are measured, the variables may be qualitative or quantitative. Those that express different characteristics or qualities will be qualitative; and they will be quantitative when they express numerical arguments.
Qualitative variations may be classified as:
 Ordinal or quasiquantitative. Here the variable will take ordered values with respect to the previously established scale.
 Nominal. The values of each variable cannot be subject to a specific order.
Quantitative variations will be classified as:
 Discreet The variable will present cuts in the scale of values that has been selected.
 You continue The variable can acquire any value while it is within a certain range of values.
Depending on the influence, the variables can be classified in a totally different way:
 Independent variable. The value assigned to the variable will not depend on another variable. They are represented within the axis of abscissa.
 Dependent variable. The value or values of a variable will depend exclusively on the values obtained by other variables.

What are the variables for?
In science , the term variable is used to refer to the objects and their characteristics that are present within the scientific hypotheses that are being studied.
The variables may be of a different nature, and may be behavioral, observable or unobservable depending on their relationship with the researcher. However, the most important variation occurs with respect to its dependence: in many cases the scientist tries to deduce a supposed link between a cause and an effect, and there we will find dependent variables and independent variables.
In the mathematical variables they are also used: they are present in formulas, and algorithms propositions . The idea of independent and dependent variables is also seen, highlighting the mathematical functions that allow the conformation of graphs of two or more axes: the relationship between these two axes is given by a function in which one of the two is variable depending on the another, which is invariable (Y is equal to half of X, has Y as a dependent variable and X as independent).
In statistics , the variable is also used in the mathematical sense, from the same perspective: when measured in different cases, it adopts different values. An internal classification divides the statistical variables as they express numerical quantities (quantitative or continuous variables) or express characteristics, qualities or modes of behavior (qualitative or discrete variables).
The computer programming , on the other hand, takes the concept of variable and uses it to explain the spaces in the main memory of the computer , reserved to store values that represent types of data supported by a programming language particular. They are data structures that can change content in the course of developing a program. Variables have ways of being recognized from the rest, labeling in some way and thereafter, referring to it when that label is named. Variables are the basis of programming of computers, being the only way to result in the action that the programmer really wants.