Nick Fury is S.H.I.E.L.D. and Samuel L. Jackson is the Ultimate Marvel Comics Universe Nick Fury. Samuel L. Jackson was Nick Fury in the Ultimate Marvel Universe comics even before appearing in a cameo in Iron Man as seen above. Nick Fury first appeared in 1963 in the war comic as Sargeant Fury. A few years later, he appeared again as the international spy extraordinare agent of S.H.I.E.L.D. Using a youth serum called the Infinity Formula, Fury has continued to operate with S.H.I.E.L.D. up until today. We know nothing of the history of Fury in the Cinematic Universe. We don't even know how he lost his eye. Hopefully we will get to see and know more of Samuel L. Fury in the S.H.I.E.L.D. series, if at the very least in cameo form.
An ordinary guy who is loving seeing his favourite superheroes being brought to life on the big and small screens, and is hopeful that the best is yet to come.