In CentOS/RHEL version 5 and 6, you can update your system using the following command:
yum update
This command will update all installed packages to the latest version available in the configured repositories. You can run this command regularly to keep your system up-to-date with the latest security patches and bug fixes.
Note: Before you run the yum update command, it is recommended to check for any updates to the system’s package metadata by running the following command:
yum makecache
This will ensure that you have the latest information about available package updates.