Task: Explanation
Input (English): Joseph Hill Whedon ( ; born June 23, 1964) is an American screenwriter, director, producer, comic book writer, and composer. He is the founder of Mutant Enemy Productions and co-founder of Bellwether Pictures, and is best known as the creator of the television series "Buffy the Vampire Slayer" (1997–2003), "Angel" (1999–2004), "Firefly" (2002), "Dollhouse" (2009–10) and "Agents of S.H.I.E.L.D." (from 2013). Question: What is the difference between Joss Whedon and Sylvester Stallone as directors?  Answer: television series
Output (English):  He is the founder of Mutant Enemy Productions and cofounder of Bellwether Pictures, and is best known as the creator of the television series Buffy the Vampire Slayer 1997–2003, Angel 1999–2004, Firefly 2002, Dollhouse 2009–10 and Agents of S.H.I.E.L.D. from 2013.