I am unaware of the different varieties of coffee. I have heard names like latte, expresso, etc. but do not know the differences between those and what are some other varieties. Since this is a stackexchange on the very topic, some details would be welcome.
There are many, many, many types. In order to give a good overview, some background knowledge is useful. What all types of coffee have in common is that all are produced from the pits of coffee cherries, the fruits borne by trees in the genus coffea (coffee beans are technically seeds of these trees, not beans). Coffee cherries are harvested from coffee trees, the pits are removed and processed, producing green coffee beans. These are then roasted, ground, and brewed.
Coffee can vary on any of the following factors:
Bean Variety - There are two major bean varieties of coffee: arabica and robusta. Arabica coffees are more ubiquitous and generally regarded as superior in quality to robusta coffees. If you are buying coffee from a coffee shop, ordering it at a restaurant, or brewing it at home, there is a very good chance you are drinking an arabica variety. Robusta is easier to grow and a less temperamental crop than arabica, contains quite a bit more caffeine, and generally is poorer quality than arabica. Robusta varieties are often used in instant coffee.
Processing Method - There are two major processing types for green coffee beans: washed and unwashed. Washed coffees remove the cherry before the bean is left to dry, while unwashed coffees have their beans removed from the cherries after drying. Unwashed coffees often come from Africa and Indonesia and have richer, earthier flavors, while washed coffees often come from Latin America, and are smoother and fruitier.
Geographic Origin - One of the most important factors, as coffee flavors vary greatly with geography, climate, and soil composition. For example, Ethopian coffees tend to be rich, full-bodied, and wine-like, Hawaiian coffees like Kona tend to be more acidic (flavor term, not pH), and Latin American coffees tend to be more medium bodied, fruity, and floral. Roast - Roasting is a complex process that can produce varying degrees of flavor and caffeine content. Roasts levels can include light/half-city, medium/full-city, full (Viennese/Italian), and double (French), in order of increasing boldness. Contrary to popular opinion, lighter roasts tend to have more caffeine than darker roasts. A good illustration of the process can be found here: http://www.sweetmarias.com/roast...
Brewing method - Can include drip filter, french press, percolated, espresso, or other methods. Brewing method also makes a big difference, with coffee aficionados generally preferring french press and espresso.
The most expensive type of coffee is Kopi Luwak from Sumatra, Bali, Java, and Sulawesi. Kopi Luwak roughly translates to "civet coffee" in English, and is called such because the beans are harvested from the droppings of civets (a cat-like mammal from Indonesia). The beans are supposedly of superior quality because the civets choose only the ripest coffee beans to eat from coffee trees, and are processed in a unique way by the civets digestive tract. Kopi Luwak often sells for around $300/lb.
The following are the different types of coffee drinks that you may find in a cafe that prepares coffee using the espresso coffee making method:
Affogato- This is a term that literally means 'drowned'. It is the description of a shot of separately served espresso that is later poured over a the top of a scoop of vanilla ice cream or gelato. This beverage is usually served in a short drink glass and is a Italian desert favourite. Popular Affogatos include Vanilla Affogato, Mocha Affogato, and Peppermint Affogato.
Americano- Also known as "Lungo" or "Long Black" and made by diluting 1-2 shots of espresso with hot water in order to approximate the texture, flavor and body of an American-style drip coffee. Said to have been originally devised as a sort of insult to Americans who wanted their Italian espresso diluted.
Babycino- A cappuccino styled drink served in an up-market café typically for children. It consists of warm milk in a small cup and topped with milk froth and chocolate powder. No espresso coffee essence is added. Breve: A term in Italian that means short and is used to describe an espresso coffee drink made with a half-and-half light cream or semi-skim milk instead of full fat milk
Caffe' Freddo- Chilled, sweetened espresso served in a tall glass, often on ice.
Caffe Latte or “Latte”- A ‘premium milk coffee experience’. Freshly steamed milk without foam served in a tall glass with a shot of espresso coffee. Caffe Mocha: A combination of chocolate syrup and a shot of espresso, topped with steamed milk and a layer of micro-foam. Finished with a sprinkled of chocolate.
Cappuccino Chiaro- (AKA Wet or Light cappuccino): Cappuccino prepared with more milk than usual.
Cappuccino Scuro- (AKA Dry or Dark cappuccino) Cappuccino prepared with less milk than usual.
Cappuccino: “Cap”- A ‘traditional morning heart starter’. Steamed foamed velvety milk poured over one shot (1) of coffee oil extract made from 12gm of freshly ground beans producing 38ml of essence. Finished by topping with foam and a sprinkle of chocolate powder. Served in a pre heated vitrified ceramic cup.
Con panna- Like the beverage "macchiato", but whipped cream is substituted for steamed milk.
Cortado- means "cut" in Spanish so the double shot espresso served in a demetesse glass supported with a metal handle is "cut" with an equal part of hot milk, making it in between the size and strength of a macchiato and a cappuccino. It is popular in Spain and Portugal, as well as throughout Latin America and Cuba, where it is drunk in the afternoon. Variations include more froth on top than a traditional cortado and occasionally with different names such as Piccolo or Gibraltar. Thanks to Ryan Cerbus for the entry.
Corretto- Espresso "corrected" with a touch of grappa, cognac, sambuca, or other spirit.
Doppio- Italian term for double. Double Espresso or twice the amount of coffee and twice the amount of water. Basically it describes two shots of espresso in one demitasse container.
Espresso con Panna- A variation of the macchiato by substituting a dollop of whipped cream for the milk froth. Basically a Starbucks invention. Means in Italian "espresso with cream”.
Espresso Lungo- American term where a shot is extracted longer for a bit of extra espresso. Tends to maximizes the caffeine but will mostly produce a more bitter cup.
Espresso Romano- Espresso served with a lemon peel on the side. Whilst not a typical accompaniment in Italy it is commonly served with the espresso beverage in America.
Flat White- “White Coffee” - ‘uncompromising taste’.Steamed microfroam milk poured through and under the espresso crème produced from one shot (1) of coffee extract made on 12gm of freshly ground coffee producing 38ml of essence. Served in a pre heated vitrified ceramic cup. A common espresso coffee order in Australia/New Zealand. Great for latte art!
Hammerhead- A coffee drink only served in the USA. It is an American term for a shot of espresso in a coffee cup that is topped up with drip-filtered coffee. As Kris Rosvold explains in the comments: In Oregon, the hammerhead is usually known as a red eye and uses 2 shots of espresso topped up in a 16oz travel mug with drip coffee. It's also sometimes called a "shot in the dark".
Irish Coffee- Coffee mixed with a dash of Irish whiskey and served with cream on top.
Latte Macchiato- Steamed milk served in a tall glass rather than a cup that is “stained” by a shot of espresso coffee.
Long Black- Often called the “American”. It is the ‘benchmark coffee without milk’. It is pure coffee made from one & one half shots of coffee extract made on 16gm of fresh ground beans producing 50ml of essence blended with steamed water. Served in a pre heated vitrified ceramic cup with the essence floated over the top of a cup filled with hot/boiling water. It is a standard espresso (Short Black) but lengthened by the addition of hot/boiling water.
Lungo- An espresso made by purposely allowing more water to flow through the ground coffee than usual. (sometimes called an Americano or ‘long’).
Macchiato- Meaning “stained” - Described as ‘strong, marked or stained’. A touch of steamed foamed milk added to a double shot of coffee extract made from 24gm of fresh ground beans producing 75ml of essence. Served in glass.
Mazagran- A French drink composed of cold coffee and seltzer water. First created by the French soldiers in 1840 in the town of Argelia. A variation includes iced coffee made with maraschino.
Quad- An espresso drink made with four shots of coffee.
Ristretto- (Ristretto in Italian means "restricted, shrunk or short”) It is the richest and most concentrated espresso drink where less water but the same amount of coffee is used to make the beverage and creates a less bitter espresso. The extraction time is shortened producing as little as 3 oz of liquid per serving. Pure and intense espresso served in a demitasse cup. Short Black: A ‘pure intense Italian favourite with a biting crème head. Contains 75ml of pure double shot (2) coffee essence made from 24gm of fresh ground coffee beans. Traditionally served in glass and is referred to as Espresso by European customers.
Viennese Coffee- Brewed black coffee of any roast or origin topped and served with whipped cream.
If you reached this part then remember. The list doesn't stops here my fried...!!!
All the best.