Pottery is the material from which the potteryware is made, of which major types include earthenware, stoneware and porcelain. The place where such wares are made is also called a pottery (plural "potteries"). Pottery also refers to the art or craft of the potter or the manufacture of pottery.

The definition of pottery used by ASTM is "all fired ceramic wares that contain clay when formed, except technical, structural, and refractory products." Some archaeologists use a different understanding by excluding ceramic objects such as figurines which are made by similar processes, materials and the same people but are not vessels.

Background - Pottery is made by forming the clay body into objects of a required shape and heating them to high temperatures in a kiln which removes all water from the clay, which induces reactions that lead to permanent changes including increasing their strength and hardening and setting their shape. Prior to some shaping processes, clay must be prepared. kneading helps to ensure an even moisture content throughout the body. Air trapped within the clay body needs to be removed. This is called de-airing and can be accomplished by a machine called a vacuum pug or manually by wedging. Wedging can also help produce an even moisture content. Once a clay body has been kneaded and de-aired or wedged, it is shaped by a variety of techniques. After shaping it is dried and then fired.

Physical stages of clayClay takes on varying physical characteristics during the making of pottery.

Greenware refers to unfired objects. Clay bodies at this stage are in their most plastic form. They are soft and maleable. Hence they can be easily deformed by handling.
Leather-hard refers to a clay body that has been dried by exposing it to the air for a period of time. At this stage the clay object has approximately 15% moisture content. Clay bodies at this stage are very firm and only slightly pliable. Trimming and handle attachment often occurs at the leather-hard state.
Bisque refers to the clay after the object is shaped to the desired form and fired in the kiln for the first time, known ss "bisque fired". This firing changes the clay in the object in several ways. The clay hardens to a form that is no longer plastic. Mineral components of the clay will undergo chemical changes that will change the color of the clay.
Glaze fired is the final stage of some pottery making. A glaze may be applied to the bisque form and the object can be decorated in several ways. After this the object is "Glaze fired" at a very high temperature. This causes the glaze material to harden and causes the glaze and decoration to adhere to the object. The glaze firing may also harden the body still more as chemical processes continue to occur in the body.
In the making of earthenware, the object may be only "Once-fired" to create a glazed pot.

Bone-dry refers to Clay bodies when they reach a moisture content at or near 0%. This will occur after glaze firing, when that is done, or after bisque firing in the case of once-fired pottery.
Clays and mineral contentsThere are several earthen materials that are referred to as clay. Their properties of the clays differ in: Plasticity, the maleability of the body; porosity, the degree to which the fired pottery will absorb water; and shrinkage, the degree of reduction in size of a body as water is removed. The various clays also differ in the way in which they respond to different degrees of heat when fired in the kiln. Each of these different clays are composed of different types and amounts of minerals that determine the resulting pottery. There are wide regional variations in the properties of raw materials used for the production of pottery, and this can lead to wares that are unique in character to a locality. It is common for clays and other materials to be mixed to produce clay bodies suited to specific purposes. The two essential components of clay are Silica and Alumina which combine to form Aluminium silicate, also known as Kaolinite Following is a list of different types of clay used for pottery that are available in different regions of the world.

Kaolin This is sometimes referred to as China clay because it is used to make quality porcelain china. This is a form of pure clay which is 100% Kaolinite, free of any other mineral ccomponent.
Ball clay An extremely plastic, fine grained sedimentary clay, which may contain some organic matter. It is usually added to poreclain to incresase plasticity.
Fire clay A clay having a slightly higher percentage of fluxes than Kaolin, but usually quite plastic. It is highly heat resistant form of clay which can be combined with other clays to increase the firing temperature and may be used as an ingredient to make stoneware type bodies.
Stoneware clays Have many of the characteristics between Fire clay and ball clay, having finer grain, like ball clay but more heat resistant like fire clays.
Bentonite An extremely plastic clay which csn be added in small quantities to short clay to make it more plastic.
Common red clay and Shale clays have vegetable and Ferric oxide impurities which make them useful for bricks, but are generally unsatisfactory for pottery except under special conditions of a particular deposit.

Glazing
Glaze is a glassy coating on pottery, the primary purposes of which are decoration and protection. One important use of glaze is to render porous pottery vessels impermeable to water and other liquids. Glaze may be applied by dusting the unfired composition over the ware or by spraying, dipping, trailing or brushing on a thin slurry composed of the unfired glaze and water. The colour of a glaze before it has been fired may be significantly different than afterward. To prevent glazed wares sticking to kiln furniture during firing, either a small part of the object being fired (for example, the foot) is left unglazed or, alternatively, special refractory "spurs" are used as supports. These are removed and discarded after the firing.

Some specialised glazing techniques include: Salt-glazing, where common salt is introduced to the kiln during the firing process. The high temperatures cause the salt to volatize, depositing it on the surface of the ware to react with the body to form a sodium aluminosilicate glaze. In the 17th and 18th centuries, salt-glazing was used in the manufacture of domestic pottery. Now, except for use by some studio potters, the process is obsolete. The last large-scale application before its demise in the face of environmental clean air restrictions was in the production of salt-glazed sewer-pipes.
Ash glazing - ash from the combustion of plant matter has been used as the flux component of glazes. The source of the ash was generally the combustion waste from the fuelling of kilns although the potential of ash derived from arable crop wastes has been investigated. Ash glazes are of historical interest in the Far East although there are reports of small-scale use in other locations such as the Catawba Valley Pottery in the United States. They are now limited to small numbers of studio potters who value the unpredictability arising from the variable nature of the raw material.

It is believed that the earliest pottery wares were hand-built and fired in bonfires. Firing times were short but the peak-temperatures achieved in the fire could be high, perhaps in the region of 900 °C, and were reached very quickly. Clays tempered with sand, grit, crushed shell or crushed pottery were often used to make bonfire-fired ceramics because they provided an open-body texture that allows water and other volatile components of the clay to escape freely. The coarser particles in the clay also acted to restrain shrinkage within the bodies of the wares during cooling which was carried out slowly to reduce the risk of thermal stress and cracking. In the main, early bonfire-fired wares were made with rounded bottoms to avoid sharp angles that might be susceptible to cracking. The earliest intentionally-constructed kilns were pit-kilns or trench-kilns--holes dug in the ground and covered with fuel. Holes in the ground provided insulation and resulted in better control over firing.

The earliest-known ceramic objects are Gravettian figurines such as those discovered at Dolni Vestonice in the modern-day Czech Republic. The Venus of Dolní Vestonice (Vestonická Venuše in Czech) is a Venus figurine, a statuette of a nude female figure dated to 29,000–25,000 BCE (Gravettian industry). The earliest pottery vessels found include those excavated from the Yuchanyan Cave in southern China, dated from 16,000 BCE, and those found in the Amur River basin in the Russian Far East, dated from 14,000 BCE.

Other earlier pottery vessels include those made by the Incipient Jomon people of Japan from around 10,500 BCE have also been found. The term "Jomon" means "cord-marked" in Japanese. This refers to the markings made on the vessels and figures using sticks with cords during their production. It appears that pottery was independently developed in North Africa during the 10,000 BCE and in South America during the 10,000 BCE In several cultures, the earliest vessels were made either by hand-shaping or by rolling the clay into a thin round cord which was then coiled round on itself to form the vessel. The earliest history of pottery production in the Near East can be divided into four periods, namely: the Hassuna period (5,000-4,500 BCE), the Halaf period (4,500-4,000 BCE), the Ubaid period (4,000-3,000 BCE), and the Uruk period (3,500-2,000 BCE).

The invention of the potter's wheel in Mesopotamia sometime between 6,000 and 4,000 BCE (Ubaid period) revolutionized pottery production. Specialized potters were then able to meet the expanding needs of the world's first cities. Pottery was in use in ancient India, including areas now forming Pakistan and northwest India, during the Mehrgarh Period II (5,500-4,800 BCE) and Merhgarh Period III (4,800-3,500 BCE), known as the ceramic Neolithic and chalcolithic. Pottery, including items known as the ed-Dur vessels, originated in regions of the Indus Valley and have been found in a number of sites in the Indus Valley Civilization.

In the Mediterranean, during the Greek Dark Ages (1,100–800 BCE), amphoras and other pottery were decorated with geometric designs such as squares, circles and lines. The period between 1,500-300 BCE in ancient Korea is known as the Mumun Pottery Period. In the Chalcolithic period in Mesopotamia, Halafian pottery achieved a level of technical competence and sophistication, not seen until the later developments of Greek pottery with Corinthian and Attic ware. The distinctive Red Samian ware of the Early Roman Empire was copied by regional potters throughout the Empire.