Variant

1. In general, a variant refers to something that contains several similarities as something else but is not the same. 
2. When referring to Linux, a variant, also known as a distribution or distro, is a release of the Linux operating system that contains its own features. For example, "Red Hat", "Debian", and "Slackware" are all variants of Linux. Although they are all Linux, each variant contains its own packages and setup, making it different from a competing variant.

Also see: Linux, Operating system definitions