Note: Listed in order of appearance. By default, all columns supported by the post type are shown.

cb 

Checkbox for bulk actions.

title 

Post title.

Includes "edit", "quick edit", "trash" and "view" links. If $mode (set from $_REQUEST['mode']) is 'excerpt', a post excerpt is included between the title and links.

author 

Post author.

categories 

Categories the post belongs to.

tags 

Tags for the post.

comments 

Number of pending comments.

date 

The date and publish status of the post.