A number line graph is a visual representation of numbers arranged in a straight line. It helps to show the relationship between numbers, making it easier to understand concepts like addition, subtraction, and the order of numbers. Each point on the line corresponds to a specific number, and the distance between points is consistent. Number line graphs can also be used to illustrate inequalities and fractions. For example, a number line can show where a fraction falls between whole numbers, helping to visualize its value. This tool is commonly used in mathematics education to enhance number sense and problem-solving skills.