A plumber is a tradesperson who specializes in installing and maintaining systems used for potable (drinking) water, sewage and drainage in plumbing systems.
The word "plumber" dates from the Roman Empire.3 The Latin for lead is plumbum.Roman roofs used lead in conduits and drain pipes4 and some were also covered with lead, lead was also used for piping and for making baths.5 In medieval times anyone who worked with lead was referred to as a plumber as can be seen from an extract of workmen fixing a roof in Westminster Palace and were referred to as plumbers "To Gilbert de Westminster, plumber, working about the roof of the pantry of the little hall, covering it with lead, and about various defects in the roof of the little hall".6 Thus a person with expertise in working with lead was first known as a Plumbarius which was later shortened to plumber. Źródło: https://en.wikipedia.org/wiki/Plumber
Not all are complicated, because some performance takes only a few minutes.This may be the installation of a kitchen tap, especially if the owners of the house they purchased a modern faucet that is simple to install.
In recent years the standard of cooking was also the presence of a dishwasher, which helps housewife doing everyday activities related to washing dishes.
Sometimes, however, when connecting the dishwasher must be present plumber.
Water supply and sanitation has been a primary logistical challenge since the dawn of civilization. Where water resources or infrastructure or sanitation systems are insufficient for the population, people fall prey to disease, dehydration, and in extreme cases, death. Major human settlements could initially develop only where fresh surface water was plentiful, such as near major rivers. Over the millennia, technology has dramatically increased the distances across which water can be relocated, but the availability of clean and fresh water remains a limiting factor on the size and density of population centers, and is expected to remain so into the foreseeable future.Źródło: https://en.wikipedia.org/wiki/History_of_water_supply_and_sanitation.