There are three main types of potatoes:
Early Season Potatoes mature in 90 days or less. This potato type is good for any garden.
Mid Season Potatoes mature between 90 and 120 days. This type of potato is a good pick for warmer climates.
Late Season Potatoes mature 120 days and over. This potato type is great for storage. Also, this type of potato is great for cooler summer climates and for producing more potatoes.
Early and mid season potatoes tend to be determinate potatoes that grow at the level you plant the seed potatoes or a little higher. Late season potatoes are generally considered indeterminate potatoes that grow from the level that you plant the seed potatoes upward so hilling the soil is important.
There are different types of onions too.
