Variables, often referred to as factors, are elements that can change or vary in an experiment or study. They are essential for understanding relationships between different components. For example, in a scientific experiment, the amount of sunlight a plant receives can be a variable that affects its growth. In statistics, variables can be classified into different types, such as independent variables, which are manipulated to observe their effect, and dependent variables, which are measured in response. Understanding these variables helps researchers draw conclusions and make predictions based on their findings.