DNF and RPM (Fedora, RHEL)

In short: RPM is the package format of Red Hat, Fedora and SUSE. DNF is the tool that fetches packages from repositories and resolves dependencies. It replaces the older YUM.

In more detail: The rpm command manages individual .rpm files, dnf takes care of sources, versions and dependencies. Fedora now uses DNF 5, compatible with the familiar commands in newer systems.

In detail

sudo dnf upgrade            # update everything
sudo dnf install vlc        # install
sudo dnf remove vlc         # remove
dnf search word             # search
dnf info vlc                # details
sudo dnf autoremove         # unneeded packages
rpm -qa | grep vlc          # installed packages
rpm -ql vlc                 # files of a package
sudo dnf history            # history, undo function

• Repositories: /etc/yum.repos.d/*.repo. Additionally RPM Fusion for codecs and proprietary drivers.
• Groups: dnf group install "Development Tools".
• Undo: dnf history undo ID.
• Atomic variants: Fedora Silverblue and Kinoite use rpm-ostree and immutable system images.
• RHEL clones: Rocky Linux and AlmaLinux use the same tool.

See also: Package management on Linux at a glance, Immutable Linux systems (immutable distros)