A handshake is a short ritual in which two people grasp one of each other's like hands, in most cases accompanied by a brief up and down movement of the grasped hands.
Using the right hand is generally considered proper etiquette. Customs surrounding handshakes are specific to cultures. Different cultures may be more or less likely to shake hands, or there may be different customs about how or when to shake hands. Handshakes are known to spread germs.
Archaeological ruins and ancient texts show that handshaking was practiced in ancient Greece as far back as the 5th century BC; a depiction of two soldiers shaking hands can be found on part of a 5th-century BC funerary stele on display in the Pergamon Museum, Berlin (stele SK1708) and other funerary steles like the one of the 4th century BC which depicts Thraseas and his wife Euandria handshaking (see images on the right). The handshake is thought by some to have originated as a gesture of peace by demonstrating that the hand holds no weapon.
Hoplite greeting an older man with slave carrying the aspis
Funerary stele of Thrasea and Euandria. Marble, ca. 375-350 BC. Antikensammlung Berlin, Pergamon Museum, 738
Antiochus I Theos of Commagene, shaking hands with Heracles 70–38 BC, Arsameia.
There are various customs surrounding handshakes, both generically and specific to certain cultures:
The handshake is commonly done upon meeting, greeting, parting, offering , expressing gratitude, or completing an agreement. In sports or other competitive activities, it is also done as a sign of good sportsmanship. Its purpose is to convey trust, respect, balance, and equality. If it is done to form an agreement, the agreement is not official until the hands are parted
Unless health issues or local customs dictate otherwise, usually a handshake is made with bare hands. However, it depends on the situation.