In brief
column-count sets the number of columns in a multi-column area. A value of 3 can divide continuous text into three columns without rewriting it as three separate texts.
Useful to know
column-count sets the number of columns in a multi-column area. A value of 3 can divide continuous text into three columns without rewriting it as three separate texts. [1]
On a narrow screen, those columns may become uncomfortable. Check width and interaction with column-width rather than preserving one count at every viewport size.
Sources
For further detail and to check the information: