Channel Name
All existing channels will display within your channel settings.
Page Type
Structure has three page types to use within your site.
Show in page selector
This determines if this channel is available from the global or in-row "Add Page" controls. Only available for channels of the type "Page".
Default template
Channels of the type "Page" or "Listing" have defaults templates assigned to them that are used when new entries are created. This does not affect existing entries.
Make each entry a single asset
Channels of the type "Asset" have the option to Add/Edit all entries. With this enabled, each entry you add is a single editable item and authors can not add more entries. This is useful for specific bits of copy or finite items someone does not need access to add more of.