Two-dimensional graphs are visual representations of data that display relationships between two variables on a coordinate plane. The horizontal axis, known as the x-axis, typically represents one variable, while the vertical axis, or y-axis, represents another. Each point on the graph corresponds to a pair of values, allowing for easy interpretation of trends and patterns. These graphs can take various forms, such as line graphs, bar graphs, or scatter plots, depending on the type of data being represented. They are widely used in fields like mathematics, science, and economics to analyze relationships and make predictions based on visual data.