Here's an article that breaks down the various types of PureCloud-supported phones.
https://help.mypurecloud.com/articles/phones-overview/
And here's a direct link to a video that explains WebRTC using the PureCloud web-based phone (also included in the article above)...
https://ininedu.wistia.com/medias/fcl4igyqcw
Speaking of WebRTC, check this blog post out...
http://blog.inin.com/new-feature-spotlight-purecloud-web-based-phone-webrtc/#sthash.04adqdf1.dpbs