Input variables are the factors or elements that are fed into a system, model, or process to produce an output. In the context of programming or data analysis, these variables can represent different types of data, such as numbers, text, or categories. They are essential for determining how a system behaves and what results it generates. In mathematical equations or algorithms, input variables are often denoted by symbols, such as x or y. By changing the values of these input variables, users can observe how the output changes, allowing for experimentation and optimization. Understanding input variables is crucial for effective decision-making and problem-solving in various fields, including science, engineering, and business.