All content types contain common elements in the right col of your edit form display. Below is a description of these elements.
Revisions of content can be saved allowing site managers to return to a previous version of their content. Comments on the revision can be added here.
If the content being worked on is to be linked to in the main menu, that link can be set or edited here.
The URL of a page can be manually set here. If not set, the URL will be automatically generated based on the title of the page.
The excerpt is used in all search results and lists on the site. If you wish for your content to have a thumbnail present in search results, that can be explicitly set here.
The summary field can include explicit text that you wish to appear in search results. If this is not set, the summary is auto generated based on the initial text of your page.
The author of the page and date the page was authored on can be set here.