version
Definition
an instance of a KEL for an AID in which at least one event is unique between two instances of the KEL.
Source: Dr. S. Smith
Explanation
In software engineering, version control (also known as revision control, source control, or source code management) is a class of systems responsible for managing changes to computer programs, documents, large web sites, or other collections of information.
Source
KERI related
More than one version of a KEL for an AID exists when for any two instances of a KEL at least one event is unique between the two instances.
Source Sam Smith