地势或地带（英语：terrain, land relief）是指地表在水平和垂直面的起伏与规模。当对象位在水下时，则称为海深测量。

Terrain, or land relief, is the vertical and horizontal dimension of land surface. When relief is described underwater, the term bathymetry is used. The Latin Word "Terra (The root word of terrain)," is "Earth."

Terrain is used as a general term in physical geography, referring to the lay of the land. This is usually expressed in terms of the elevation, slope, and orientation of terrain features. Terrain affects surface water flow and distribution. Over a large area, it can affect weather and climate patterns.