The content tab was added in 10.5 it provides a scalable method for listing grouping and finding posts and then subsequently editing them. The post lists in the ribbon menu have been removed. The content tab also includes post based forums.
The new tab in left column in admin is title 'Content'. Clicking on the tab shows a list post type groups with their post types. Post groups can be created and ordered here, post types are added to a group here.
Clicking a post type opens the post list screen in the right panel.
The search box at the top searches posts and allows searching by partial name or body content, it will auto-suggest after three chars are entered. If a number is entered then it will search for a post with that postid.