Water Pressure Regulator & Well Water Pressure Tanks
Most homes do not have to consider things such as having their own water tower or cistern, because they live in a developed town with a water tower or other reliable water supply. If you live on a farm, or in a remote area with no water piping, then it may be necessary for you to supply your own water supply. One solution is to have your own water tower, while another is to have a water tank, which is typically ground level or underground, perhaps in a basement. In that case, gravity cannot bring water to your faucet; some other mechanism must be used to create water pressure.
Your option are either an external pump that mechanically draws water from the tank and then pumps it to your faucet, or pressurize the entire tank. Both devices are common, with the water pressure tank being slightly less preferred because of the occassional fiz and air that might spit from the tap. Well water pressure tanks are also possible, or the water is drawn from the well under its own natural ground pressure, then is sent through a filter and the force is controlled with a water pressure regulator.
Water in the tank is pressurized either by compressed air, heat, or by external mechanical force. A hot water heater is under pressure, and steam or at least the force of expansion drives the hot water. A cold water tank cannot use this method, and so typically uses air pressure. All these devices have been used for decades, and the commercially aviable devices are generally reliable and able to serve for years.
the advantages of having your own water tank is there is less risk of pipes freezing; the piping is inside your home, and the tanks are probably in the ground enough to prevent freezing. If there is a leak, you can see it, and so you are in control. If there is a problem with an external water supply, then you have your own private reservior. The major disadvantages of having a pressurized tank is that the pressurizer likely runs off electricity. Either you must plug in a generator, or you are out of running water.