in internet command/term that tells the amount of time it took your computer to respond to another computers signal. A computers internet reflex if you will. Ping refers to the other computer bouncing a signal off you computer and it bouncing, or pinging back.
Random is highly over used but when used in the correct context it should be something completely out of the blue and hilarious for example:
Jayne: So are you in Roch tomorrow?
Vicky: Yea are you?
Jayne: definatley... *sings* Ring ring ring ring ring ring ring ring BANANA FONE!!!!
Vicky: *giggles* ... random!
Both: *SING* RING RING RING RING RING RING RING RING BANANA FONE!!!!!
Jayne: I dont kno dude u threw that remote pretty fucking hard!