Wire rope is in principle made the same way as fibre rope but the numbers of wires and strands vary considerably. Instead of threads of fibre one starts with wires, so for example 36 wires may be used to form a strand and 6 strands might be used to form the 'rope'. This wire would then be referred to as a '6x36' wire; the variations of wires and strands will determine its flexibility. One other major difference with wire rope is that they all have a 'heart', that is all the strands are laid around a core (the heart) which is made of rope or wire. Flexible wires have hearts made of rope and standing rigging or rigid wires have hearts of wire.