Updated June 10th, 2019.
Here’s the WiFi menu (formerly the “Airport menu”):
And here’s the WiFi menu, showing a whole lot more info and some extra menu items.
Want to see more info about your WiFi network? Hold the Option key down before clicking on the WiFi menu icon up there in the menu bar.
You can learn a lot about your network by looking at the stuff written in gray. A lot. You should check it out.
If your wireless network isn’t working the way it should, Apple’s “Wireless Diagnostics” can help. It’s in the WiFi menu… but only if you hold the Option key before you drop the menu. That is, press and hold the Option key, then click the WiFi menu, then slide down to “Open Wireless Diagnostics.” If you don’t hold the Option key first the Wireless Diagnostics menu item won’t be there.
My friend Tom used to say “It’s always the Option key! I should always try that first!” and he was right. That goes for you too.