To find the domain and range of a graph, start by considering all real numbers as potential values. Analyze the graph to identify any restrictions, such as vertical asymptotes or holes, which indicate values that cannot be included in the domain. For the range, observe the highest and lowest points on the graph, noting any horizontal asymptotes or limits. A specific example can clarify this process, such as determining the domain and range of a quadratic function, which typically includes all real numbers for the domain and a specific interval for the range based on the vertex. Understanding these concepts is essential for accurately interpreting graphs in mathematics.