Uchiwa

A handheld fan is an implement used to induce an airflow for the purpose of cooling or refreshing oneself. Any broad, flat surface waved back-and-forth will create a small airflow and therefore can be considered a rudimentary fan. Generally, purpose-made handheld fans are shaped like a sector of a circle and made of a thin material (such as paper or feathers) mounted on slats which revolve around a pivot so that it can be closed when not in use.

The movement of a handheld fan provides cooling by increasing the airflow over the skin, which in turn increases the evaporation rate of sweat droplets on the skin, and increasing heat convection by displacing the warmer air, produced by body heat, that surrounds the skin. This evaporation has a cooling effect due to the latent heat of evaporation of water. Fans are convenient to carry around, especially folding fans.

Next to the folding fans, the rigid hand screen fan, was also a highly decorative and desired object among the higher classes. Its purpose is different since they are more cumbersome to carry around. They were mostly used to shield the lady's face against the glare of the sun or the fire.

Archaeological ruins and ancient texts show that the hand fan was used in ancient Greece at least since the 4th century BC and was known under the name rhipis (Greek: ῥιπίς). Christian Europe's earliest fan was the flabellum (or ceremonial fan), which dates to the 6th century. This was used during services to drive insects away from the consecrated bread and wine. Its use died out in western Europe, but continues in the Eastern Orthodox and Ethiopian Churches. Hand fans were absent in Europe during the High Middle Ages until they were reintroduced in the 13th and 14th centuries Fans from the Middle East were brought back by Crusaders. Portuguese traders brought them back from China and Japan in the 16th century, and fans became generally popular. The fan is especially popular in Spain, where flamenco dancers used the fan and extended its use to the nobility. European brands have introduced more modern designs and have enabled the hand fan to work with modern-day fashion.

...
Wikipedia