The network connection icon has a number of variations to let you know its status.
Red X: This means there is no network connection available
Yellow Triangle: This indicates a potential problem with the connection; it represents a warning sign
Blue Circle: This shows the network is connected to the internet; this represents the world, as in the World Wide Web
Sometimes there is a slight delay in these symbols appearing due to the system working hard on other processes, so the "connected to the internet" symbol can appear when you're not connected.
If you're still having internet troubles and can't find a solution, help is on hand. For more information, click on the link below: