Newbie question: Difference between Applying Original Texture/Baking

Say I have a model that I need to decimate to a lower poly version. The high poly model already has a texture.

Is there a difference between these two actions?:

  1. Decimating the model and applying the original texture to the decimated model.
  2. Baking the high poly model’s texture into the decimated model.

Or are they pretty much the same?