Those are the armhfp images for CentOS 7.5.1804 release. Consider reading https://wiki.centos.org/SpecialInterestGroup/AltArch/armhfp to understand how to use those images, as (except for RaspberryPi 2,3, 3B+ models) you'll need to correctly setup uboot (described in the wiki page) or your board will *not* boot