To install the Gnome desktop environment on a CentOS or Red Hat Enterprise Linux (RHEL) 7 system using the yum package manager, you can follow these steps:
sudo yum update
This will ensure that you have the latest packages and security updates installed on your system.
sudo yum groupinstall "GNOME Desktop"
This will install the Gnome desktop environment and all of the necessary packages to run it.
Once the installation is complete, you can switch to the Gnome desktop environment by logging out and selecting "Gnome" from the login screen.
If the Gnome desktop environment does not appear as an option on the login screen, you can try enabling it by running the following command:
sudo systemctl set-default graphical.target
This will set the default target to the graphical target, which will start the Gnome desktop environment when the system boots.
You can find more information about using the yum command and its options in the CentOS or RHEL documentation or by running the yum --help command.
You can find more information about using the Gnome desktop environment on CentOS or RHEL systems in the Gnome documentation or by searching online.