As the Google Reader will cease to exist in a couple of months time, you can start sniffing for the alternative RSS feed reader. Allow me to try and make it really simple for you.
Space Exploration Technologies, a private space company launched a rocket couple a days ago, and sent its Dragon space capsule to dock on the International Space Station.
If you are using Facebook social apps for watching videos, reading content and you don't want your friends or everyone to know about your activity, you can turn this off.