A masterpiece was once a job application
The word has drifted a long way. Under the medieval guild system a young worker spent years as an APPRENTICE learning from a master, then worked as a journeyman — from the French journée, a day — meaning somebody skilled enough to be paid by the day, but not yet permitted to run a workshop.
To become a master, they submitted a single piece of work for the guild to examine: the master piece. Pass, and you could set up on your own and take apprentices. The word now means the finest thing an artist ever produced; it started life as a trade test.
Roman water pipes were made of lead, and the Latin for lead is plumbum — which is why the chemical symbol for lead is Pb, and why the person who fits your pipes is a PLUMBER. The same root gives the plumb line: a lead weight on a string that hangs dead vertical and tells a BRICKLAYER whether a wall is true.
The other names are just as literal. A JOINER cuts the joints in a workshop, a CARPENTER fits the timber on site, a GLAZIER fits glass, a MASON works stone, and a FITTER fits things. The vocabulary has barely shifted in several hundred years.
Still learned by doing
An apprenticeship is one of the few routes into a career that pays from the first week. A modern APPRENTICE works alongside qualified tradespeople and spends time at college, usually for two to four years, and finishes with a recognised qualification and no student debt.
It suits the work, because you cannot learn this from a book. The skill is in what to do when the wall is not straight, the pipe is in the wrong place, the previous owner did something inexplicable in 1987, and the customer is standing behind you watching.
Why there are never enough
Skilled trades are in short supply across much of Europe and North America, for reasons that are not complicated: a generation is retiring, schools spent years treating university as the default destination, and not enough young people came through behind them.
The result is that a good ELECTRICIAN or PLUMBER can pick their work and name a fair price. Many end up running their own small businesses, which means the job quietly includes quoting, scheduling, chasing invoices and being cheerful at eight in the morning in somebody else's cold kitchen.
Every trade is applied science
An ELECTRICIAN has to understand current, resistance and earthing, because getting it wrong kills people. A PLUMBER works with pressure, gravity and the awkward fact that hot water expands. A ROOFER is thinking about wind lift. A WELDER is doing metallurgy with an extremely bright torch.
It is one of the better arguments for taking practical subjects seriously. Behind the TOOLBOX and the SCAFFOLD sits a real body of knowledge, and the people who hold it are the ones keeping buildings upright and water flowing in the intended direction.