Application wide settings are saved in between sessions so that every time you start ParaView on the same machine you get the same behaviors. The settings are stored in an XML file that resides at %APPDATA%\ParaView\ParaViewVERSION.ini on Windows and ~/.config/ParaView/ParaViewVERSION.ini on all other platforms. If you need to restore ParaView's default settings you can either move this file or run with the --disable-registry argument.
These settings are managed via the settings dialog. On Macintosh this is reached from the Preferences entry in the ParaView menu. On Unix, Linux and Windows systems it is reached from the Settings entry on the Edit menu. These settings are program wide and are not to be confused with the View settings found under the Edit menu. Those settings are specific to each View window and are discussed in the Displaying Data chapter.
The following figures show the various pages within the settings dialog. Choose from among them by clicking on the page list toward the left. Click on the arrow to expose the three sub pages in the Render View settings category. Some plugins add their own pages to the dialog but we do not discuss them here and instead refer you to any documentation that comes along with the plugin. Do note though that most settings are documented within the application via tooltips.