Final answer:
The software installation package format used on Red Hat is RPM. RPM stands for Red Hat Package Manager and it is the native package format for Red Hat distributions such as Red Hat Enterprise Linux.
Step-by-step explanation:
The software installation package format used on Red Hat is RPM (Red Hat Package Manager). RPM is an open-source package management system that Red Hat uses to distribute and manage the software in its distributions, including Red Hat Enterprise Linux (RHEL). RPM files have the .rpm extension and handle the installation, upgrading, and removal of software on your Linux system. When compared to the other options, DEB is used by Debian-based distributions such as Ubuntu, TAR.GZ is an archive format that can include source code or binaries but isn't a native installation package, and PKG is used in macOS and some other Unix environments.
When installing software on Red Hat systems, administrators or users will often use the rpm command or higher-level tools like dnf or yum (which in latest RHEL versions is a link to dnf) that rely on RPM packages and also handle dependencies automatically.