Settings (Site, Page, Theme Options)

 Site Settings

site settings are all general and public settings for WordPress websites, like site title, tagline, front page, etc.

Developers could customize these settings.

Theme Options

Any WordPress Theme has special  settings. these settings show in theme options dialog settings.

Developers could customize these settings for their themes.

Page Settings

these settings will apply only on the current page and user on each page could choose new values for options.

Developers could customize these settings.