The Jalapeno is one of the most commonly grown chiles in Mexico and probably the most common chile pepper in the U.S. When the jalapeno is smoked and dried it is called a "chipotle".
The name "jalapeno" is derived from "Jalapa" the capitol of Veracruz, Mexico. The chiles average 2" to 2 1/2" in length and about 1" in diameter.
The use of this chile dates back to the Aztecs who were the first known to smoke the chiles. Jalapenos are so thick and fleshy that they can't be dried to preserve them because they'll rot before they will dry.
The Jalapeno is considered a moderate to hot chile or a 5 on a scale of 1 to 10 (10 being the hottest).
The Jalapeno is very versatile and is used fresh, roasted, filled, as well as pickled. It can be diced and used in fresh salsas and pico de gallo or atop any dish where a little extra "heat" is desired. The pickled versions are commonly used as a condiment.