A line graph is a visual tool used to display data points over a period of time. It consists of a horizontal axis (x-axis) and a vertical axis (y-axis), where each point represents a value. By connecting these points with a line, you can easily see trends, patterns, and changes in the data. For example, a line graph can show how the temperature changes throughout the year. Line graphs are commonly used in various fields, such as science, business, and education. They help people quickly understand complex information, making it easier to compare different sets of data. For instance, a student might use a line graph to track their grades over a semester, helping them visualize their progress.