• Custom Post Type Gallery: Switch to Off to disable the Galleries custom post type altogether and remove it from the main menu.
• URL Rewrite: The text displayed in the URL when you view a single gallery page. For example, set this to gallery for your URLs to look like site.com/gallery/gallery-name.

After changing this field go to Settings → Permalinks → Save Changes.

• URL Rewrite Name: The name displayed in the breadcrumbs when you view the single gallery page.