In science and mathematics, variables are often used to represent real world quantities that are unknown or can change. For example, if I earn $10 for every hour of work I do, how much I have at the end of the week will be determined by how many hours of work I did during that week. How many hours of work I do and how much I earn are both variables but one of them depends on the other.
An *independent variable* is one that is changed or controlled in a scientific experiment. It represents the cause or reason for an outcome. The *dependent variable* variable on the other hand is the variable that is being tested or measured in the experiment.
In the above example, my *independent variable* is the `number of hours` of work I do. I have total control over it and directly changing it cahnges the *dependent variable*, which is `how much I would have earned` at the end of the week.
