This page shows all the information related to a particular ticket. The status of a ticket, the due date, the priority, any milestone or category that the ticket is associated with. Also, any assignees that are on this particular ticket will display in the header.

When posting a comment on a ticket, notice that you can mark your comment as the solution for the ticket.

This will place a tag on that comment as the solution to the ticket and shade the background of the comment to a highlighted color.