Wireless LAN – 802.11 frequency bands (WiFi Channel) Explained

I have read many books on this concept and have viewed lot of other sources along with many videos and you sir are the 1st person to make this concept sink into my brain. What you call it, the penny finally drops or the lightbulb turns on. Thank you. A great video.

Exe.

Since channel 1,6 and 11 are not overlapping with each other and If I have 2 APs (operate in 2.4 band) both set to channel 11 is there going be interfering with each other ? OR I should set one AP to channel 1 (or channel 3) the other AP should be set channel 11 ?

Why is 20 MHz used in 2.4 GHz and not lower bandwidths?