Digital surface model and Digital terrain model

how can i display digital surface model and digital terrain model in cesium?

Welcome to the Cesium Community!

To add terrain to the globe, you can use the code below:

var viewer = new Cesium.Viewer("cesiumContainer", {
  terrainProvider: new Cesium.createWorldTerrain()

Can you clarify what “digital surface model” mean? For instance, are you looking for 3D buildings?