Chipotle are smoke dried jalapeno peppers.  You can purchase them dried or canned in adobo sauce.  I usually prefer the dried, since I can reconstitute as few or many as I need. Update, the chipolte pictured below were extremely mild. I never had them this mild. I wonder if they were mismarked since jalapenos are usually smaller. There is also a rule of thumb that the smaller the pepper the hotter it is.

If you do use the canned version you can freeze the remainder for future use.

Used in Crab & Guacamole “Margaritas”