DescriptionTypicality is routinely invoked in science and mathematics: typical gases in a low-entropy macrostate evolve to a higher-entropy macrostate; typical quantum systems exhibit probabilistic behavior; typical realizations of percolation models with p>1/2 contain an infinite open cluster. And typicality facts like these back many explanations. But what is it for something to be typical? And how do typicality facts explain? In this paper, I analyze the notions of typical properties, typical objects, and typicality explanations. I show how typicality is used to explain mathematical, statistical mechanical, and quantum mechanical phenomena. Finally, I argue that typicality is distinct from probability.