As Facebook grows, it becomes a platform for new forms of communication. From comments to "Likes," friends are able to reach out to you in a variety of formats. For each type of incoming communication that you receive, Facebook gives you a notification. Notifications appear in the banner at the top of your Facebook screen.
Comments And Posts
Notifications for new wall posts and comments left on your status updates appear in the upper left corner of any Facebook screen, just above the globe icon. In addition to a written explanation of each notification, Facebook provides a small symbol. A green box with quotation marks means that someone added a new post to your wall or left a comment under your post. A thumbs up sign means that a friend "liked" your post, and an orange square means that someone commented on a photo of yours.
The new message symbol appears immediately to the left of the globe icon, in the top left corner of your Facebook screen. The symbol consists of two overlapping square text bubbles. When you click on the icon, your five most recent message conversations appear in a drop-down window along with a short preview of the message. The thumbnail picture of the friend with whom you are messaging also appears next to the message.
When you receive a new incoming friend request, a notification appears just above the symbol of two overlapping heads, located immediately to the left of the messages symbol. Click on the symbol to see the thumbnail and name of the person who is requesting to connect with you. To see the full request, just click on the name of the sender.
All new notifications are indicated by a red flag over the appropriate symbol. The small white number in the middle of the flag represents how many new notifications you have. For example, a red flag with the number "5" inside of it located over the messages icon tells you that you have five new unread messages.