Washed coffees (aka wet process) use water to remove the coffee seed from the cherry. This has the least amount of contact with the fruit and has a clean and often creamy taste. Washed coffees are commonly known to carry more flavours from the origin, terroir and variety rather than the processing flavours.

Natural coffees were popularised by producing countries that did not have as much access to water, this processing technique has since been adopted all over the world and tends to carry through a rich fruity flavour from the extended contact with the coffee cherries,

There are many coffees that fall into this third category of coffee processing, the most popular being Anaerobic fermentation and Carbonic Fermentation (CM).
Expect funky fruity notes and an intense alcohol / boozey taste