Facebook chat question?

[Just Awkward ok]

When someone is online, the green dot is beside there name.
But sometimes the green dot would be there then it could change to a "phone" symbol after a few minutes, then the green dot will appear again, then the phone symbol etc.
Does this mean they keep logging in and out of Facebook?

[Inam H]

it's not that because people usually use the app and than back out to do something else on their phone and than they use the app again which is why you keep seeing the phone and green dot symbol

[Alex]

If the green dot is on that means there on facebook. If the mobile phone icon is displayed that means their not on it but their logged into facebook from their mobile phone and still receive notifications.