In a Mac OS the status of WiFi (AirPort) is generally displayed on Mac menu bar. This is very useful to know whether your Mac system is connected to any network and the current status of the network connection. In case if your Mac system does not show the status on the Menu bar then you can turn on the WiFi status using the options provided as part of Network Preferences.
Click the Apple menu and select System Preferences from the list of available menus.
In the System Preferences window, navigate to Internet & Wireless section and click the Network option.
In the Network window, tick the check box with label as Show AirPort status in Menu bar.
This would display the Airport status in menu bar as shown below