Anecdotal reasoning is a type of hasty generalization fallacy, wherein a broad generalization is grounded in a single short narration (or just a few such short narrations).

Here is an example:

Millie: "Chico's shoes always stink." ​Katrina: "How do you know that?" ​Millie: "Because yesterday I picked up his basketball shoes from the porch, and (scrunches nose): Pew!"

Millie's reasoning is fallacious because one unpleasant instance of smelling a pair of Chico's shoes does not mean all of Chico's shoes are always so odoriferous.