The in-kernel CIFS filesystem is generally the preferred method for
mounting SMB/CIFS shares on Linux.
The in-kernel CIFS filesystem relies on a set of user-space tools.
That package of tools is called cifs-utils. Although not really part
of Samba proper, these tools were originally part of the Samba package.
For several reasons, shipping these tools as part of Samba was problematic
and it was deemed better to split them off into their own package.