In addition to posting a reply to a topic, you can also send a Personal Message - PM. A PM goes to a specific member and is not seen by anyone else. To send a PM all you have to do is click on a member name that is appearing in blue. This will open that members profile and at the top you will see in Send Personal Message. Click this and a message screen will open. If someone sends you a personal message you will see the popup stating you have a Personal Message and clicking it will take you to your message box.