It has always been considered an unfortunate thing that Freud's language was translated from German into Latin terms rather than English because you lose the intimacy of the original language. The ID, the Ego and Superego were originally Das Es, Das Ich and Das Uber Ich—the it, the I and the over-I, which is more evocative. The Id which is "the it" is an indeterminable morasse of emotions that lie below the I—the Ego, which is who we are to the world and to ourselves. According to Freud (though not Anna Freud and the Ego Psychologists), the Id is the primary source of psychic energy. The ego was like a rider on a horse, which is the id, barely containing its impulses.
The Id acts according to the pleasure principle, seeking gratification of the drives and avoiding pain. The drives consist of the libidinal, aggressive and then eventually the death drive (which was developed late into Freud's career). Anyone who has been around any group of people under stress (or on the internet) and who often sees people devolve to fucking or fighting knows that Freud wasn't wrong. As far as the death drive, there is this idea around quiescence, which is stillness and hibernation and the body's desire to relieve itself of the hunger of the drives and go into a state of rest. Death is seen as the ultimate state of quiescence. It's not coincidental that this theory was developed around WWI, when Freud witnessed the most destructive war in European history up to that point.
So what is that little gremliny id telling you today?