You can download EZcast for Mac and start mirroring your Mac screen on a larger screen (eg TV) with the help of WiFi Ezcast Dongle.
I have installed Ezcast software on my Macbook Pro running OS El Capitan version 10.11.2 and I can now display my Macbook Screen on my HDTV wirelessly.
If I browse the internet on my mac, watch movie etc, it all displays on my TV wirelessly. I can be watching NetFlix movies on my Macbook and be watching it on my TV too. The Ezcast software simply turns my TV to a projector screen.
You can download Ezcast for Mac here from Ezcast website. It requires Mac OS 10.9 above.
You will be required to sign up before you can download the EZcast software for Mac. You can sign in With Facebook or Google+ account though..
The Ezcast application for Mac supports extension and mirror with audio transmission. It also supports music and video streaming.
After installation, ensure you restart your mac to complete the installation.
You can download EzCast for Windows PC here.