There seems to be a lot of hype around chipotle, but I think a lot of it is just using it as a catchphrase. But chipotle is a very specific thing: a smoked jalapeño. They typically wait until the peppers are dark red, at which point they’re already somewhat dry inside. They’re then smoked until they’re completely dry, imparting a smoky flavor. Jalapenos can lose up to 90% of their weight while being smoked. The Wikipedia page has more information, and photos, but first, a warning: the photos of chipotles on Wikipedia are repulsive-looking.