Surface　roughness　has　an　important　influence　on　the　service　performance　and　life　of　parts.　Areal　surface　roughness　has　the　advantage　of　accurately　and　comprehensively　characterizing　surface　microtopography.　Understanding　the　relationship　and　distinction　between　profile　and　areal　surface　roughness　is　conducive　to　deepening　the　study　of　areal　surface　roughness　and　improving　its　application.　In　this　paper,　the　concepts,　development,　and　applications　of　surface　roughness　in　the　profile　and　the　areal　are　summarized　from　the　aspect　of　evaluation　parameters.　The　relationships　and　differences　between　surface　roughness　in　the　profile　and　the　areal　are　analyzed　for　each　aspect,　and　future　development　trends　are　identified.