Using the On and Off options, you can hide objects on selected layers. The On, Off, and Freeze options are in the layer dropdown menu of the Layers panel and also on the LAYER PROPERTIES MANAGER palette.

In the drawing that we are using in this section, we have the Doors, Furniture, Walls, and Plants layers. I will use this drawing to explain this topic. Click on the layer dropdown menu on the Layers panel and click on the light bulb icon next to the Doors layer. You will notice that the light bulb icon will turn gray and all doors from the drawing on that layer will disappear. The doors are still in the drawing and when you click on the light bulb icon next to the Doors layer, the doors will once again show up in the drawing area:

Alternatively, you can also turn the light bulb off from LAYER PROPERTIES MANAGER palette, as shown in the following figure:

To bring back doors, click on the gray light bulb icon next to the Doors layer once again and the objects on the layer will show up. When you click the light bulb icon on the active layer, a warning message will show up (see the following figure). You can choose to keep the layer on or turn it off despite it being the current layer:

The icon next to the light bulb icon that looks like the sun is for freezing a layer. Click on the freeze icon next to the Furniture layer and the icon will turn into a snowflake icon and all the objects on the Furniture layer will also disappear from the drawing area. Although visibly the On/Off and Freeze options seem the same, they work differently:

When you freeze a layer, AutoCAD removes it from memory as well and the layer won't be refreshed when you regenerate your drawing. Freezing a layer is especially helpful in drawings containing large datasets, where you can freeze layers that are currently not in use; this improves the performance of the drawing as AutoCAD no longer has to refresh data from layers that are frozen.

To thaw or unfreeze a layer, click on the snowflake icon in the freeze column and the objects on that layer will once again show up. The current layer will not freeze even when you try to freeze it and a pop-up message will show up when you try to freeze the current layer.