"Ceramic Tile" is sometimes the general category referring to all tile products. But there are distinctions within that category worth noting. Tile that is ceramic is typically made from clay-based materials, then glazed and fired to the desired hardness.
Ceramic tends to cost less than porcelain and still offers excellent design choices, especially for wall tile applications where lighter-weight ceramic is often preferred. Ceramic can usually be cut with "score-and-snap" tile cutters whereas porcelain most often requires a diamond-bladed wet saw. Labor prices for tile tend to be some of the highest in the industry due to the intricate, meticulous nature of tilework, but professional installation usually provides the most satisfying results.
Porcelain has a higher density and is harder than ceramic tile because it is made from sand or silica-based materials, and is glazed and fired at much higher temperatures. Porcelain is typically the floor tile of choice for high traffic or heavy use areas like kitchens. Some porcelain tiles are even rated for outdoor use and can withstand freeze/thaw cycles. Full wall and floor series are available in porcelain, often with top-of-the-line texturing technology and more natural-looking, random pattern variation.