In India, the Pali term for what we call “son” was jhana (dhyana in Sanskrit).
When Buddhism entered China, the Chinese pronounced jhana as ch’anna.
Ch’anna was abbreviated to ch’an.

In Korea ch’an was pronounced as son and in Japan it was pronounced as zen.
The word jhana originally means “quiet thought” and “cultivation through thought.”
It is often translated as “meditation.”

In Korea, the term chamson is often used and there are two ways to understand this word.

According to the first way, the meaning is simply the sum of its component words.
Cham means “to participate” and son is “son.”
So chamson means “to participate in son.”

According to the second way, chamson is viewed as an abbreviation of the phrase ch’am-nye-son-ji-shik-mun-son, which means “ To a Good and Knowledgeable Friend of Proper Conduct, ask of son.”
In other words, if in the course of son practice a question should arise, ask an enlightened master.

Chamson here refers to the entire tradition of self-cultivation that arose when Shakyamuni Buddha became enlightened to the Middle Way which avoids the two extremes of self-indulgence and self-mortification.

For the sake of convenience, we’ll refer to chamson as “son practice” and understand it to contain both meanings of son meditation and the whole tradition of Buddhist spiritual practice.