I'm not understanding this 1080p on phones business, isn't 1080p 1920 x 1080? Now theres phones comming out claiming they play 1080p videos yet the screen's resolution is far less than 1920 x 1080. Can someone please explain this to me.
It doesn't have so much to do with the size of the screen, but rather how many vertical and horizontal pixel lines they can cram into a given screen. So, a 720p screen will have 720 vertical and horizontal lines (each way), hence why you get high definition. 1080p is the same way.
Correct. The resize is done by the hardware, i.e. compression. So basically, smart phone tech is has advanced to the point where a given phone can "handle" a 1080p video in the sense that it is converted to the screen size, yet looks ultra sharp and clear.