A:Answer Roku has over 2500 channels (apps) built in, and the majority are free. Google Chromecast is something that you use from your smart phone or tablet, and lets you stream from your phone or tablet to the TV. The Roku you have a dedicated remote control and you can install the Roku app to have it act as another remote, with Chromecast your device is the remote. The Roku plugs into one of the three HDMI inputs, while Chromecast is built in. If you want Chromecast Ultra (the 4k Ultra HDR) version then you have to plug that into one of the HDMI slots as well.