There is an option to turn Default Content Protection On/Off for all content.
This allows you to set if you want all newly created Pages and Posts set to either Protected or Not Protected by default (note that you can always change this setting later).
So, if the majority of your Pages and Posts are going to be Protected, you will likely want the Default Content Protection setting On.
If you want the majority of your Pages and Posts not protected then you will likely want this setting turned Off.
Note that the protected content will still require Access to be set to allow membership levels to view it.
Also, any existing content was that not protected before this setting was turned On would not be changed. Any existing content that was not protected would need to be manually set to protected as this setting does not change existing content settings.