On most circuit boards today, the preferred resistive element used is the mounted fixed resistor.  These are commonly a small, rectangular discrete device that has metallic coatings/contacts at each end that can be soldered directly to the top of the board.  They are durable components as long as specifications are kept, and they are easily mounted onto solder points on a predesigned board.

The construction of these resistors is actually quite similar across a large range of ohmage ratings.  This is accomplished by varying the size of the actual cross section and length of the resistor as opposed to changing the elements contained within.  Since a longer resistor and a thinner resistor both would have a much higher impedance than a shorter or wider resistor, very accurate and precise resistive ratings can be achieved on fixed single mounted resistors.  The chemical composition of the device is usually some form of an oxide coating a ceramic element in the center.  Lasers are then used to grind the coated ceramic into an exact width and length so as to reach the correct impedance which keeping variability quite low.