how to delete unused layer - autocad

Autocad users can delete unused layers in autocad drawings type in command line pu (Purge All Unused Layers) and enter or do the following step see below video.

Or Click Home tab => Layers panel => Layer Properties.2- In the Layer Properties Manager, choose the layer and click the Delete Layer button.

Note:-

Layers that are not empty cannot be removed until all objects using the layer are reassigned to a different layer or are deleted. This requirement includes objects in blocks that reference the layer.The PURGE command also can remove layers.Layer 0, DEFPOINTS, and the current layer cannot be removed.