How to find which package certain command belongs to on CentOS?

Ubuntu / Debian example to check the package of the free command:

dpkg -S $(which free)

Query the rpmdb.

rpm -qf $(which free)

For CentOS, how about yum provides?

Use

which free 

to find out where it is

For me it's at

/usr/bin/free

So then you can run

yum provides /usr/bin/free

and it will tell you which package has it