Logitech C920 Web Cam

Logitech C920 with Hardware Compression

Be sure to install the drivers... it will work using Microsoft Windows UVC drivers if you don't, but the experience may not be optimal.  You should go here and http://www.logitech.com/en-us/webcam-communications/webcams/devices/hd-pro-webcam-c920  Click on the Support Link and then click on the software downloads link on the right side of the page.
 

If you are planning on using the camera with Skype it is also recommended that you update to the latest version of Skype to take advantage of the capabilities of your new Logitech C920 HD camera.

Because of the cameras built in video compression this offloads this function from you CPU and allows the camera to do the work.  You should see an improvement to performance while using this camera versus other cameras like the Logitech C910 which do not include this feature.