What does the x-axis represent on a coordinate plane?

The x-axis on a coordinate plane represents the horizontal number line. This axis is used to display the values of the independent variable in a two-dimensional graph, where the horizontal direction corresponds to positive and negative values. When plotting points on a coordinate grid, the x-axis is where you locate the first number in an ordered pair, indicating how far to move left or right from the origin, which is the central point of the graph.

Understanding the distinction between the x-axis and y-axis is fundamental in mathematics, particularly for graphing linear equations or functions. This horizontal line effectively serves as a baseline from which vertical positions (represented on the y-axis) can be measured. Therefore, recognizing the function of the x-axis as a horizontal number line is key to interpreting and analyzing data represented in graphical form.