The \cline command draws horizontal lines across the columns specified, beginning in column i and ending in column j, which are identified in the mandatory argument.
It is used in the tabular and array environment.
Two (or more) successive \cline commands draw lines in the same vertical position. Typically, these are placed after a \\ (line breadk) command so that they separate items on two lines; they do not, however, need a line break command afterwards.