Running, it's all about the float.

Neophyte runners often wonder if they are running or jogging. This reminds me of the facetious definitions of runners and joggers, respectively: In the 1980s, we were called "joggers." In the 1990s, we were called "runners". In the 21st Century, we are "endurance athletes." 

Elitists are found in any avocation. Running is no exception. Some faster runners will denigrate slower ones by claiming that the latter are not running; they are jogging. This is specious. Wikipedia has the following definition: "Running is a method of terrestrial locomotion by which humans and other animals move rapidly on foot. Running is a gait with an aerial phase in which all feet are above the ground (though there are exceptions)." I note for clarity that the exceptions cited in the definition refer to birds. The bottom line is if both feet leave the ground at some point in your stride, you are running.

In all fairness, Wikipedia also includes an article on jogging. "Jogging is running at a gentle pace; its definition, as compared with running, is not standard. In general, jogging speed is between 4 and 6 miles per hour (6.4 and 9.7 km/h). Running is sometimes defined as requiring a moment of no contact to the ground, whereas jogging often sustains the contact."

Both definitions refer to the moment when both feet come off the ground. This is the float phase, and every runner who wants to run faster aims to maximize the time in this phase.