What command is used to install updates on a system?

What command is used to install updates on a system?

• A. apt update
• B. yum update
• C. dnf upgrade
• D. rpm refresh

Answer: (B)

The correct answer is related to the command used within the context of package management in Linux distributions that utilize the YUM package manager, primarily Red Hat-based distributions such as CentOS and Fedora. The command `yum update` refreshes the list of available packages and their versions, then downloads and installs any newer versions of the packages currently installed on the system. This command is vital for maintaining the system's software by applying necessary updates for security, bug fixes, and performance improvements. The other choices refer to different package management commands or systems. For instance, `apt update` is the command used in Debian-based distributions like Ubuntu, specifically to update the package list, and does not install updates. Similarly, `dnf upgrade` serves a similar purpose as `yum update` but is used in newer versions of Fedora and other related distributions, replacing YUM. Lastly, `rpm refresh` is not a valid command, as the RPM package manager does not have a refresh command like the other package managers mentioned. Each command plays a distinct role depending on the Linux distribution being used, but in the context of your question, the use of YUM for installing updates is the correct reference.

The correct answer is related to the command used within the context of package management in Linux distributions that utilize the YUM package manager, primarily Red Hat-based distributions such as CentOS and Fedora. The command yum update refreshes the list of available packages and their versions, then downloads and installs any newer versions of the packages currently installed on the system. This command is vital for maintaining the system's software by applying necessary updates for security, bug fixes, and performance improvements.

The other choices refer to different package management commands or systems. For instance, apt update is the command used in Debian-based distributions like Ubuntu, specifically to update the package list, and does not install updates. Similarly, dnf upgrade serves a similar purpose as yum update but is used in newer versions of Fedora and other related distributions, replacing YUM. Lastly, rpm refresh is not a valid command, as the RPM package manager does not have a refresh command like the other package managers mentioned. Each command plays a distinct role depending on the Linux distribution being used, but in the context of your question, the use of YUM for installing updates is the correct reference.