In short it is like this , you have a wire going through an ferromagnetic ring, you can have two poles , pass the current in one way and you have N S pass it the other way and you have S N ,So for a given input you have either one or the other output , now insert the binary code in all of this and you get either 0 or 1.
have many of these wires going through many rings and you have many ones and zeros and now you can compute some information. + you can store it because the ferromagnetic piece if not distracted will stay at it's last state for a while (keeping it's magnetic polarity) atleast some materials tend to do this.