User blog comment:Auslly~Bobbie~Music/Talk Like Crazy!/@comment-8433788-20130803185629/@comment-26014718-20130804010800

Basically cancelled means that the network doesn't want that show to continue, either because of low viewers or the actors are to busy to continue filming, therefore the show doesn't get a proper series finale ending. Whereas ending is when the writers themselves choose to end the show because they feel it's had their run or they just simply run out of ideas, giving it a proper ending.

For example iCarly ended with a series finale after 6 seasons by the writers, and Victorious was cancelled by Nickelodeon and didn't get a proper ending (like it deserved).