@Ernest Bywater
They were indentured servants that were usually connected to the land they worked and who bossed them about was the person who was the legal owner of the manor land.
Not quite, but almost.
"Indentured" was where you provided service for a set period of time. Normally to absolve a debt, or in exchange for training or a grant upon the completion.
But what they were was tied to the land itself, then up through a web of titles and allegiances. Normally they worked for a Knight or land granted man at arms, who worked for a Baron. Who worked for a Count. And that Count may work for a Duke-Earl, or may call directly under the Monarch.
However, here is where the difference between "Serf" and "Peasant" comes in. A Serf was indeed bound to the land, but did not own rights to it. These were the lower workers. Muckers of stalls, hewers of wood, unskilled laborers. Peasants were a step up, and had rights to home, hearth, and land.
But neither could be "bought, sold, or traded", they were not slaves. However, if they were bound by contract that contract could be sold. But once fulfilled, they were still released.
Franklins or "freemen" were the "free agents" of the era. Normally they had useful skills, but were not tradesmen under a guild. Hunters, foresters, animal husbandmen, and the equivalent of "master famer" were typical roles. They would swear an oath of loyalty, but were free to leave whenever they wanted.
However, by the same token if their services were not needed, they were dismissed.
This is something I actually started researching decades ago, as part of tracking human migrations. It was during the early middle ages that "last names" as we know started to be used. But not in connection to "family", but trade.
"Mark the Fletcher" would have a son who also became a Fletcher, so became known as John the Fletcher. And they just dropped the article and became "John Fletcher".
Fletcher, Thatcher, Cooper, Smith, Cook, Driver, Farmer, Wright, Franklin, Clark, Letterman, those all became "last names" because they were the jobs of the people who started to use them in that way. And to differentiate between people, as "Jacob the Cooper" might live next door to "Jacob the Letterman".
Terry Jones actually did a great series all about that era in Europe. And in it he busts a lot of myths. Most only know him as a comedian from Monty Python, but he actually had a degree from Oxford in Medieval History.
And was a respected scholar in both medieval history and medieval literature. And after retiring from comedy, spent most of his time writing books on the subject as well as documentaries about everything from numbers and life in the middle ages to following ancient maps and the Barbarian Invasions.
https://www.youtube.com/watch?v=QquhNTBfpdw