If you are using the Google Chromecast device and you want to cast from your laptop or computer you need everything running from within Google Chrome browser and even from the browser, you need to install an extension for the Google Chromecast telecast.
In case you don’t know what is Google Chromecast it is a small device that you can attach to your TV (your TV needs to have an HDMI port) and then you can use your mobile phone or tablet to watch movies and other streaming media on your TV. This is how it looks:
Once you have attached the Google Chromecast device to your computer and then connected the device with your mobile phone you can watch YouTube, Google Play Movies, Netflix and even images in your Google Photos account. Although there is no problem when you are playing media from your mobile phone, from a computer everything needs to happen within the Google Chrome browser and this is why you need to install an extension. Once you have installed the extension, you can connect to your Google Chromecast device from your laptop or PC and as long as you’re playing the media within your browser, everything shows up on your TV.
Since both Google Chrome and Google Chromecast come from Google it was but natural that casting would become inbuilt within Google Chrome. Another reason for this development might be that the Chrome OS requires you to work within the browser all the time and if you want to broadcast media from your laptop to your TV, you should have to rely on an extension.
The casting feature isn’t publicly available yet. It is available in the beta version of Google Chrome.