The Porter style finds it's roots in England, and typically have a light to medium body with a great balance. They have a low to mid hop bitterness and are known for their malty flavor. Most Porters are made with chocolate and caramel malts, which gives them their characteristic "roasted" flavor profile they are so well known for.
Stouts are darker beers that are crafted using roasted malts and barley that are known for their rich flavor and dark color. Typically, stouts are a stronger beer with a higher alcohol content than their Porter cousins. Irish Stouts, Imperial Stouts, Oatmeal Stouts, and Milk Stouts are just some of the different stout styles you can find.