rr rather, a continuous arc.
It seems to be a common opinion (especially on /co/) that cartoon episodes were always self-contained in stories and that Avatar started it to be much "anime-like" to have a progressive story.
To which I say is bullshit - I mean, older cartoons like Teddy Ruxpin, Transformers, G.I Joe, Jayce and the Wheeled Warriors, Adventures of The Galaxy Rangers, Inhumanoids, Jem, ThunderCats (both versions) , DuckTales, and then later with shows such The Legend of Prince Valiant, Invasion America, Princess Gwenevere and the Jewel Riders, X-Men, Spiderman, Iron Man, Fantastic Four, Incredible Hulk, Double Dragon, King Arthur and The Knights of Justice, Shadow Raiders, The Pirates of Dark Water, Conan the Adventurer, Exosquad, Phantom 2040, Beast Wars, Gargoyles, Reboot, Superman TAS, Silver Surfer, Batman Beyond, Xyber 9: New Dawn, Redwall, XMen Evolution, As Told By Ginger, TMNT (later 1987 series episodes and 2003 series), He-Man (both 1983 and 2002 versions), Jackie Chan Adventures, Static Shock, Justice League/Unlimited, Argai: The Prophecy, Chris Colorado, WITCH, Xiaolin Showdown, Danny Phantom, Codename Kids Next Door, Teen Titans, American Dragon (Season 2), Kim Possible (Season 4), Avatar: The Last Airbender, Transformers Animated, Star Wars: The Clone Wars (2003 and 2008 series)/Rebels, Ben 10 (OS and UAF), The Batman, Legion of Superheros, Total Drama, Speed Racer The Next Generation, Wolverine and The X-Men, Spectacular Spiderman, Iron Man: Armored Adventures have definite continuity and a story that moves forward. You would never understand future episodes without watching older ones.