What Do the Colored Circles by Friends' Names Mean on Facebook?by Matt Koble
Facebook chat uses a couple of icons to signify who is using Facebook chat and in what capacity. Understanding these icons helps you determine when best to start a chat with a particular friend and when best to pick someone else to chat with. If she isn't online, your chat conversation probably won't get very far.
When a friend appears in the Facebook chat window with a green circle next to her name, it means she's currently online and available to chat. When you send her a message via the chat window, she'll instantly receive it and see it in her Facebook window. Facebook first displays people you regularly or have recently interacted with. Everybody else currently online appears lower in the chat window under the "More Friends" heading.
Friends with a cellphone icon next to their name are not online on a computer, but receive Facebook chat messages directly to their phones. These people use one of the official Facebook or Facebook Messenger apps for their phone. When you send this friend a message, it will be delivered to his phone. Facebook automatically remembers your chat conversations, so you can also switch from your phone to your computer without losing the chat history.
No icon next to a name in the Facebook chat window means that friend is not currently on Chat. If you start chatting with such a friend, the things you say won't instantly pop up on her screen, like they would if the friend was online. Instead, chat messages sent to an offline friend are delivered directly to her Facebook messages. The next time she logs on to Facebook, she'll have a notification for a new message, where she'll see whatever you sent via the chat window.
Facebook Messenger Apps
Facebook has downloadable versions of Facebook Chat for Windows, Firefox and Smartphones. Using one of these "Messenger for" apps provides the same symbols you see when using Facebook chat on the actual website. For example, with Messenger for Windows, an online friend still show up with a green circle next to her name. When you use a third-party instant messaging platform like Pigdin, Adium and AIM, the symbols you see next to friends may differ.