Activate Enable Real-Time Effects to apply the Rendering options. Disable Enable Real-Time Effects to apply the Rendering options only when rendering with the Render window.

For example, if Use Antialiasing is activated, and you disable Enable Real-Time Effects, Anti-aliasing is only applied when rendering to a file.

Anti-aliasing refers to a method of softening hard edges in a display that occurs as a result of sampling and over-sampling.