Intended for viewing by mature audiences, graphic in this context is a synonym for explicit, referring to the clear and unabashed nature of the violence portrayed.
[1][2] On the internet, the term is used as a catch-all for footage capturing real incidents of extreme body destruction, such as mutilation, work accidents, and zoosadism.
In fictional depictions, appropriately realistic plot elements are usually included to heighten the sense of realism (i.e. blood effects, prop weapons, CGI).
In order to qualify for the "graphic" designation, the violence depicted must generally be of a particularly unmitigated and unshielded nature; an example would be a video of a man being shot, bleeding from the wound, and crumpling to the ground.
Graphic violence arouses strong emotions, ranging from titillation and excitement to utter revulsion and even terror, depending on the mindset of the viewer and the method in which it is presented.
A certain degree of graphic violence has become de rigueur in adult "action" genre, and it is presented in an amount and manner carefully deliberated to excite the emotions of the target demographic without inducing disgust or revulsion.
Even more extreme and grotesque acts of graphic violence (generally revolving around mutilation) are often used in the horror genre in order to inspire even stronger emotions of fear and shock (which the viewing demographic would presumably be seeking).
Violence in films is not an old topic, recently a study presented in an annual American Academy of Pediatrics conference showed that the "good guys" in superhero movies were on average more violent than the villains, potentially sending a strongly negative message to young viewers.
This kind of media might depict reality footage of war, car crashes and other accidents, decapitations, suicide, terrorism, murder, or executions.