Solid construction is the most common type of cookware. It has a solid metal body, and often comes with a non-stick finish. Ply construction cookware also called Clad cookware, has multiple layers of metal bonded together, often around a copper or aluminum core. This type of cookware is heavier and provides very uniform heat distribution but is generally more expensive than solid cookware.
Often stainless steel cookware features a base coating or bonded core of aluminum or copper. These metals are superior conductors of heat relative to stainless steel and improve the heat distribution and overall performance of the cookware.