The difference between CentOS Linux and CentOS Stream
CentOS Linux is a rebuilt version of Red Hat Enterprise Linux (RHEL). Therefore, it is downstream of RHEL. CentOS Linux release numbers reflect the date of the RHEL release on which they are based. For example, CentOS 8.2105 is a rebuild of RHEL 8 released March 2021.<>.
On the other hand, CentOS Stream is the upstream public development branch of RHEL. Specifically, CentOS Stream 8 is upstream for the next minor release of RHEL 8, CentOS Stream 9 is upstream for the next minor release of RHEL 9, and so on.
Since centos Linux is a reconstruction of the current RHEL release, there will be a large number of updates for new minor releases, with smaller updates provided between minor releases. And for CentOS Stream contains content for upcoming RHEL minor releases. In short, Centos Linux is updated slowly, and CentOS Stream is updated more frequently.
Differences between CentOS 7 releases
CentOS-7-DVD version: DVD is a standard installation disk, generally you can download this one.
CentOS-7-NetInstall version: network installation mirror.
CentOS-7-Everything version: Supplements the software of the full version installation disk and integrates all software.
CentOS-7-GnomeLive version: GNOME desktop version.
CentOS-7-KdeLive version: KDE desktop version.
CentOS-7-livecd version: the system running on the CD, similar to winpe
CentOS-7-Minimal version: the smallest installation disk, only the necessary software, and the least built-in software
The difference between 2009 and 2207?
Both 2009 and 2207 are just a release of centos7.9.
2207 ISO only works with xtra hardware support or timezones. Older 2009 ISOs are not supported as of September 2020 release.
You should only use the 2207 ISO if you have problems with the 2009 ISO.