Reaching the height of its popularity in the late 1600s, Delftware vases, tiles, and plates were, in their heyday, customary objects d’art in the great majority of households in the Netherlands. Some of the finer examples became highly prized collectors items.
 
Delftware is a type of faience (earthenware pottery covered in a thick white tin glaze) painted with most often blue but sometimes multicolored designs.  Unlike porcelain - which is pure white in color and somewhat translucent, faience (also known as majolica) is actually a brown to light beige earthenware covered by an opaque layer white tin glaze.
 
Originating in Italy, the technique allegedly appeared in northern Europe when a potter Guido Andries (also known as Guido da Savino) started to create faience-ware in the city of Antwerp in the early 16th century. When the VOC (Dutch East Indies Company) began importing Chinese porcelain into the Netherlands, its ensuing popularity resulted in the production of locally produced faience imitations… especially after the imports of Chinese porcelain decreased.
 
With the passage of time, these imitations actually became more popular than the original Chinese imports themselves. By the middle of the 17th century the potteries of Delft (renowned for their skilful imitation of Chinese porcelain), brought their city fame as the centre of painted faience production, hence the name that comes down to us to this day: ‘Delftware’. In fact, as time progressed, the artisans of Delft began producing pottery that, in the eyes of the local population at least, surpassed the quality of latter Chinese porcelain potteries vainly trying to copy their ancestors’ earlier styles.
 
These Chinese imitations were not the only Delftware products produced; native Dutch motifs were also in demand… featuring windmills, hunting scenes, animals, cityscapes, landscapes, and seascapes. As well as dinner plates, service sets, and vases, Delft potteries also produced hundreds of millions of tiles. To this day, several Dutch homesteads contain kitchens decorated with hundreds of these tiles.
 
Towards the middle 18th century the quality of Delftware produced declined, and as the century wore on most Delftware potteries went out of business. Today, only two factories producing Delftware remain: the Tichelaar factory in Makkum, Friesland - founded in 1594; and De Koninklijke Porceleyne Fles in Delft, south Holland - founded in 1653.
 
Sources:
 
http://www.mark-norton-fine-antiques.com/delftware.htm

http://www.rijksmuseum.nl/

http://en.wikipedia.org/wiki/Delftware