The x-axis is one of the two main lines in a graph, typically running horizontally from left to right. It helps to represent values or categories, making it easier to visualize data. For example, in a graph showing the growth of a plant over time, the x-axis might display the days or weeks, allowing us to see how the plant's height changes. In a coordinate system, the x-axis is paired with the y-axis, which runs vertically. Together, they create a grid that helps us plot points and understand relationships between different variables. This system is widely used in mathematics, science, and economics to analyze trends and patterns.