There is a link below to a related question whose answer provides more information and which has a number of links, "What was a life for a serf?"
No, a serf was a good deal lower than a knight. A serf was an agricultural worker who was bound to the land he lived on and was not allowed to leave it. A serf was not a slave, because he could not be purchased or sold, but he was also not free to leave the place where he lived. The knights were the lowest level of nobility. They were at a higher status than freemen, who were at a higher status than serfs.
1st AnswerSerf is the latin word for "slave" so a serf wasn't allowed to leave their land without the lord's permission.2nd AnswerThe Latin word for "slave" was servus, and the word serf is derived from it, just as servant is. Serfs, however, were not slaves, and, aside from the fact that they were bound to the land and had to pay rent, they were allowed to do pretty much as they pleased. Being bound to the soil meant that they were legally not allowed to move away from the manor where they lived without permission. There is a link below to a related question whose answer provides more information and which has a number of links, "What was a life for a serf?"
Whats serf
The homonym for "serf" is "surf."
Your question is not entirely correct in its premise; a serf is not a slave and does not have an owner. A serf is a subject of a land owner whom the serf would address as lord.
In medieval times, most agricultural workers were serfs. They were bound to their lands, meaning that they were not exactly slaves, but they were not allowed to move away from their homes. They were given plots of land to tend, and there were plots of land worked by the serfs in a community as a group. They were not paid, for the most part, but got the food they grew, protection, and a place to live.
In a feudal system, a serf would remain a serf no matter how hard they were to work.
Saint Serf died in 583.
Saint Serf was born in 500.
Riddle answer: a serf board.
The plural of the word "serf" is "serfs."
The noble executed the serf.