A cup is a specialized vessel crafted for holding water while serving its primary purpose of holding alcohol or tea for consumption. Typically, cups feature a moderate volume and come in a variety of shapes and sizes. Ancient Chinese civilizations used a cup known as the gaiwan for tea drinking. In their basic form, cups run straight or open with the diameter of the rim typically mirroring the cup's height. Some cups come with circle, flat, or elevated feet. The Neolithic age marks the earliest presence of cups as evidenced in archaeological ancient pottery finds from Hemudu, Yangshao and Longshan culture sites. During this time, cups were diverse in shape and style, ranging from cone-shaped and three-legged to tall handle and goblet-shaped. Presently, cups can be made from a range of materials such as glass, plastic, ceramic, wood, and stainless steel.
Cups come in various types that can be categorized based on the material used, including ceramic, glass, plastic, stainless steel, wood, and cloisonné. Likewise, cups can be classified according to their functions, such as daily use cups, advertising cups, promotional cups, thermos cups, and health care cups. Based on their meaning and purpose, cups can also be categorized as acacia cups, couple cups, and couple cups. Finally, the structure and technology used to make cups can also be used to classify them into single-layer cups, double-layer cups, vacuum cups, nano cups, energy cups, and ecological cups.