“Boarding” means living on campus, which is the meaning of a boarding school.
History of boarding school is long.
In Europe, the history of the boarding school began in the 12th century during the Middle Ages when Pope Benedict ordered
all monasteries to teach children how to write.
Therefore, the first boarding school was a monastery. Only the monks were literate during the dark Middle Ages.
This was prior to the invention of a printing press so the monks spent most of their days copying and duplicating the Bible.
These monasteries were located in remote areas that were far from towns, so the children had to board at the monasteries to learn to read and write.
Boarding was possible since the monks lived at the monasteries.

Boarding school expanded during the British Empire when the colonial British families wanted to educate their children with the British teachings.
Great Britain had many colonies in the New World, India, South Africa, China and more.
Rather than sending their children to the local schools, the British families built and educated their children at the boarding schools.
Therefore, the British boarding schools have the longest history.

British built boarding schools in the New World for the same purpose.
Junior boarding schools like Fay School, established in 1866, began boarding children at age 13 while senior boarding schools like Phillips Academy Andover, established in 1778, focuses on high school boarding. Their boarding practice continues till today.
With time and through change, their education was centralized.
In our 21st global age, it is wise to look at the boarding schools' teachings and what the education they pride on.