And since wireless routers usually can operate directly out of the box, they are not secured by default.Head on to the advanced wireless settings if your router features it. Here you can fine tune the routers wireless network to work more efficiently.
The easiest way to manage your routers settings and wireless network is...

Furthermore, visual representations like the one above help us fully grasp the concept of Best Practices For Securing Wireless Router Settings.
Wi-Fi & Wireless 5 Tips for Securing Your Wireless Network.

[Wireless Router] How to set up ASUS Wi-Fi router via ASUS Router App?
Step 2: Update the Wireless Security Settings. Once logged in, navigate to the wireless configuration section. The exact menu names vary by router manufacturer but are typically labeled Wireless, Wi-Fi Settings, or Security.