Once you've clicked on this tab you will have a few options
, but I think the best place to start is the selection that shows your current connection. Once you've checked your current connection you may need to restart your connection, completely reconnect, or repair your connection. I've found that 90% of the time this is sufficient to restore your Internet connection and nothing else needs to be done. If however this is not the case then you will likely need to go in a little bit deeper to check the status of your connection, and quite possibly you might find out that your internal or external hardware is on the way out and needs to be replaced.