I am not known for my brief answers, so buckle in. I am capitalizing the Master and Grand Master title as it is a honorific.
We have to start all the way in the beginning. It'll become clear in a bit why we have to do this.
Traditionally, European boys were sent to apprentice with a Master in their (or their father's, more likely) chosen craft at age fourteen. For three years, this Master was both trainer and parent in one. His job was to ensure the boy's holistic education, a God-fearing, hard working craftsman. In exchange for hard labor (seven days a week, with the exception of Easter at home), not all of which was job related (think "wax on, wax off"), the Master provided room, five meals a day, and access to hand-me-down clothes and sometimes a small salary ("Lehrgeld" in German speaking countries where this practice was most prevalent and remains active).
After three years, the boy was allowed to show his craft to the local guild's Masters. If deemed sufficient, he was released from his Master's service and sent to be a journeyman. If you ever wondered where that title came from, here's the goods: for one year, starting with the day the guild approved the Master's request, our newly minted non-apprentice was not to return home or to his old Master's place. A so-called "ban mile" was established (it was, in fact, 30 kilometers, not just a mile) that the journeyman was not allowed to cross. He was also not allowed to stay at any one location for more than one month or six weeks, depending on time of year.
This practice, the journey after one's apprenticeship, has mostly died out. In Europe, only carpenters, bricklayers, and similar professions still do it. Journeymen are dependent upon the goodwill of strangers, work for as many bosses as possible, and are not allowed any possessions aside from a small sack with clothes, a watch, their tools, and a hat.
Here's a picture of journeymen in their traditional garb. The practice has changed very little since its institution in the 16th century - cellphones, personal belongings, even using public transit is explicitly forbidden. Flights and hitch hiking are allowed, however.
After that year, a journeyman became a companion ("Geselle") to an established Master. Drawing upon their references from jobs done while on their journey, the companion sought out their boss and were now allowed to demand wages and other considerations. Well-referenced journeymen started to make real money at that point in their career.
Six years down the road, five of which had to be spent under a guild-appointed Master, a companion was allowed to request a Master certification for themselves. To gain this, he had to subject himself to the questions of the guild for ten days, work with a guild Master for another four months, sit with the guild's "rat" (council) and observe, and then prepare his "Meisterwerk," his master piece, for consideration.
If he passed, and less than ten percent do at the first try, even today, he was allowed to call himself a Master and take on apprentices. Which is where we loop back to the next generation. Only a craftsman experienced in the rigors of working up the ladder, approved and in good standing with their guild, and rich enough to take on apprentices was allowed to carry the title Master.
In very rare circumstances, rare enough to only yield six in all of Europe, a Master can become a Grand Master by virtue of being the head of a guild, having fifty years of Master time, twenty years as a guild official, and having trained at least ten apprentices, eight of which have to have gone on to become Masters themselves. If all eight apprentice-now-Master craftsmen vote in a secret poll for the promotion, the Master is henceforth to be addressed as "Grossmeister" or Grand Master.
Fast forward to today:
Apprenticeships still last three years, but most apprentices live outside their Master's homes. Laws regulate the amount of time an apprentice is allowed to work and what they are allowed to do. Pay is also not as bad, healthcare and savings accounts are mandatory. Once a week, apprentices attend school, the parent/teacher function has been broken up and mostly removed.
There are few journeymen these days, and fifteen percent are women. Companions only need to spend eight years in the industry to be granted the right to sit for their Master exam, which is administered by the chamber of commerce or industrial chamber instead of the guilds.
In the United States, all you have to do to get a snazzy piece of paper saying "Master Chef" is to pay the ACF $4,000 and sit through a few tests which are below the rigors of an apprentice in Europe.
Or you can participate in Gordon Ramsay's idiotic show.
The Grand Master requirements did not change, however. And that's good.More questions on Chefs: