Water flow
The maximum water flow during the operation of the tap, in other words, the maximum amount of water that it can pass through in a minute. This characteristic is important, foremost, for models designed for baths (see "Suitable for"): the greater the throughput, the faster the bath will fill. However, the meaning of this paragraph is not limited to this. First, flow information can be useful in certain calculations related to water supply — for example, to calculate the required pump capacity. Secondly, high-end taps can be equipped with aerators to achieve a powerful and efficient jet with low water consumption; the consumption indicated in the characteristics allows you to evaluate the efficiency of such devices in comparison with analogues.
Max water pressure
The highest inlet pressure at which the tap is able to operate in a trouble-free mode with minimal risk of premature failure. In other words, this is the ultimate strength of the tap. Note that for normal east european use, it can be assumed that the maximum pressure in the water supply is 6 bar. One should focus on that value and choose a model with a small margin of max pressure in order to avoid leaks in the tap nodes during pressure surges in excess of the norm. Note that in plumbing with a centralized water supply, the pressure can reach 10 bar. Therefore, for expensive taps that make high demands on the inlet pressure, it is necessary to buy special reduction gears.
Inlet communication
The type of water pipes the tap is designed for.
— Hoses. With a flexible connection type, polymer tubes (hoses) are used to connect the tap to the water supply, which can bend well and are reinforced with a metal mesh for strength. This ensures ease and versatility of attachment — thanks to the flexibility of the pipe, it can be carried even in cramped places. On the other hand, such a supply is less durable and reliable than a rigid one. It is mainly used in models for kitchens and sinks (see "Suitable for"). Installation pipes may be included in the package of the tap; this point should be clarified separately.
— Rigid pipes. Such taps are designed for installing directly to metal water pipes. The advantage of this type is reliability and strength, the disadvantage is significant restrictions on the installation site: you either have to put the tap where the pipes were made during construction, or redo the communications, which is associated with great inconvenience and cost. On the other hand, such taps are usually used for bathtubs and showers, and in modern bathrooms, typically there are no problems with unsuccessful installation of pipes.