The essential part of the package description is the information defined in the Name, Version, and Release (NVR) spec file directives. RPM uses this information to compare package versions and track package dependencies.

When working with RPMs, you can also see mentions of EVR (epoch-version-release), NEVR (name-epoch-version-release), and NEVRA (name-epoch-version-release-architecture). EVR is the full version information of the package that RPM always uses for comparison. RPM compares one component at a time, starting from the first component. RPM stops the comparison when it finds a difference in components. For example, if Epoch differs, RPM does not compare the rest of the EVR components.

You can display the NVR information for a specific package by querying the RPM database, for example:

# rpm -q bash
bash-4.4.19-7.el8.x86_64

Here, bash is the package name, 4.4.19 is the version, and 7.el8 is the release. The x86_64 marker is the package architecture. Unlike NVR, the architecture marker is not under direct control of the RPM packager, but is defined by the rpmbuild build environment. The exception to this is the architecture-independent noarch package.