There are over 33 species and about 3729 varieties of Chili’s. Mexico alone produces and uses 140 varieties! I have short-listed a few of the more commonly known ones, with some specifics about them.
I normally don’t like to generalize but for simplicity sake, the SMALLER the Chili, the HIGHER the heat.
Hungarian Sweet Paprika
Sweet heat, from Hungary. This mild Pepper is cone-like in shape and cultivated till it turns red, then picked and dried. It is sometimes called Pimento but that would not be the Hungarian type.
Originally from French Guyana and named after the Cayenne river. This is one of the more typical chilies; in fact, cayenne is what most people think of when they think “Chili.” Long, thin and if left to ripen can attain maximum levels of heat. There are many, many varieties of the Cayenne, including the Long Slim, the Carolina, the Golden and on and on. They are very high in Vitamins A and C
Sweet heat and relatively mild – sometimes known as California Chili or Chili Verde. They are a pretty normal chili unless you get into the more interesting varieties like Anaheim TM or New Mexican Chili, which is great roasted, or the Anaheim M.
Very high on the heat scale and very very popular in Caribbean cooking. It is sometimes known as the Habanero Pepper as they are closely related. it is available in the UK in green, yellow, orange, white, brown and red as well as multi-toned. One of the tastiest and hottest. Please eat with caution!
A general name given to many varieties of the common pepper found at supermarkets in green, red, orange, yellow and sometimes purple. It is sweet by nature and low on the heat scale. The green peppers are undeveloped versions and less ripe, many find them harder to digest.
A medium to high heat pepper. Chipotle is a general name for any smoked pepper. A true Chipotle is greyish tan and looks more like a cigar butt than a pepper.
A medium heat pepper and I’d say the most popular. Interestingly enough, it was named after the city it comes from in Mexico Xalapa, and is not grown there anymore. When left to ripen to red can be very sweet.