Dongles are devices which attach to TVs to stream Internet media. They make smart TVs out of dumb TVs.
There are a lot of them out there and few places to compare them.
They are different in what media they will stream and what technology they use to do it.
A Microsoft dongle has just been released and a Google Android dongle will be available in January .
The Microsoft technology uses the oldest but simplest Miracast system. It beams data direct from a device to the TV. Most dongles work through a router. This new dongle has a high speed processor.
I could not make it work with any of three Windows devices, including a Windows phone, a Windows Surface RT and a Windows 8.1tablet.
However, it worked beautifully and simply with my Nexus 5 phone. It mirrors the phone's screen. It did the job better than earlier Miracast devices I have seen.
The Apple TV device was the first I found that would mirror a computer or tablet. It works beautifully with an iPad.
The more recent Chromecast dongle works with a variety of devices and uses a unique technology whereby it channels through the device and can hand off to the router to continue its other device work separately. I found that awkward, though.
The Roku is the oldest streamer with which I am familiar. I use it mainly to stream PBS , but it has the largest access to other streaming media.
The Android device sells for $39 or even less if you are an Amazon Prime user. This dongle also uses the Miracast technology.