To frezee or turn on/off??

2d? probably doesn't make any difference at all to you. 3d? big difference, freeze removes items from regenerations. off will still hide & takes up considerable memory in large drawings.

Frozen items are not calculated in the model, as if they didn't exist. Items turned off are calculated, but not displayed. This has numerous ramifications, beyond regens. If a block has entities in it that are on layers A, B, and C, and the block is on layer D, the model will behave differently if layer D is frozen or just turned off. If frozen none of the entities in the block will display. If D is off, they will all display, presuming that A,B, and C are still on and thawed. There are similar situations with viewports, and 3d models as Longshot described.

freezing layers makes them still visible but unalterable.
david

I believe that is locking the layers.
Chris

That's NOT true. Are you familiar with this application?

Never used Autocad, eh?