The difference between pipes and tubes is simply in the way it is sized.
Copper tube, CPVC, PeX and other tubing is measured nominally, which is basically an average diameter.
These sizing schemes allow for universal adaptation of transitional fittings.
Tubing, in particular copper, comes in rigid hard tempered "joints" or soft tempered (annealed) rolls.PeX and CPVC tubing also comes in rigid "joints" or flexible rolls. The temper of the copper, that is whether it is a rigid "joint" or flexible roll, does not affect the sizing.7 The thicknesses of the water pipe and tube walls can vary. Pipe wall thickness is denoted by various schedules or for large bore polyethylene pipe in the UK by the Standard Dimension Ratio (SDR), defined as the ratio of the pipe diameter to its wall thickness.
Pipe wall thickness increases with schedule, and is available in schedules 20, 40, 80, and higher in special cases.
Copper tubing is available in four wall thicknesses: type DWV (thinnest wall; only allowed as drain pipe per UPC), type 'M' (thin; typically only allowed as drain pipe by IPC code), type 'L' (thicker, standard duty for water lines and water service), and type 'K' (thickest, typically used underground between the main and the meter).Because piping and tubing are commodities, having a greater wall thickness implies higher initial cost.
Thicker walled pipe generally implies greater durability and higher pressure tolerances.Źródło: https://en.wikipedia.org/wiki/Water_pipe#Difference_between_pipes_and_tubes
This is because the state of the responsibility of owners of housing blocks and homes can have installations mounted a dozen years earlier.Similar situation may occur also in the case of hospitals.
While carrying out efficient assembly of the shower may require the presence of two employees of the hydraulic system..