The measurement of surface roughness is a crucial tool for characterizing engineering surfaces. After more than 20 years of development, areal surface roughness has become a key factor that reflects the characteristics of engineering surfaces. This study includes summaries and comparisons of the characteristics of areal surface roughness, contact and non-contact measurement methods, and nanometer-scale surface roughness analysis methods. The applications and limitations of existing methods are also analyzed, and the direction for future development is presented.