Great way to save as well as present pork rillettes; Mason jars rubber ring and all. Looks great on the table with crusty bread. Spreadable.

"A piece of pork, goose, duck or turkey cooked in its own fat and stored in a pot, covered in the same fat to preserve it." - Larousse Gastronomique
The classical definition has been adapted to mean any food cooked long and slow in a large quantity of fat.

It's also a way of cooking vegetables in fat long enough that they caramelize and break down and become sweet and unctuous. Check out these 2 recipes:
http://www.food52.com/recipes/6533_onion_and_red_pepper_confit
http://www.food52.com/recipes/2558_tuscan_onion_confit

Confit can refer to more than one thing. Typically it is a preservation method of cooking where meat, such as duck, is cooked immersed in fat. This can be done with other things like artichokes or garlic as well. Confit can also refer to fruits that are preserved in sugar.