I admit I have a caftan obsession. I always have. They are perfect in the summer; all floaty, comfortable and cool.
There are many, many different types of robe-like garments with different purposes, and they vary by country. There are different forms of caftan or kaftan worn in Turkey and Morocco, for example, and other styles are popular in some areas of Southeast Asia.
The burnoose is a hooded cloak, not a closed garment like the caftan. It originated in the Arab countries as well. The Indian kurta is similar to the caftan in that it is very long, loose, and collarless.
Also from India is the salwar kameez, in which the salwar is the pants and the kameez is a long shirt or knee-length tunic of silky, flowing fabric in a slightly more fitted style than the caftan. The dashiki is a long tunic which originated in Africa as a sleeveless shirt for men.
When it reached the US fashion scene in the 1960s it morphed into the rectangular pullover-style shirt with sleeves. If made in an ethnic print or decorated with heavy embroidered trim, it is still recognized as an “African” garment. The muu-muu is a loose-fitting Hawaiian dress. It is a very full dress which floats loose around the body.
Each of these originated in a hot or humid climate.
Of course I like to design fancy, embellished caftans to wear to elegant affairs, in silk, or bejeweled velvets. These are great for any time of year. Mine are available at Bergdorf Goodman, on the 4th fl. in the Evening Dept. (photo of Amy Zerner caftan by Monte Farber)