- the DVD images contain most of the packages but not all,
- the Live media images are also stored on DVD and allow you to decide to install the distribution or not with a reduced number of packages,
- the Livecd image, stored on a CD, is a basic distribution,
- the Everything image contains all the available packages.
In addition, the CentOS 7 FAQ gives you some tips:
- How to activate your Ethernet network interface during the installation,
- How to keep the old network interface names,
- How to disable IPv6.
This is a good news for those who want to start to learn RHEL 7 but can’t afford to pay the fee.