The difference between extruded acrylic and cell cast acrylic is in the manufacturing process. Extruded acrylic is made by heating a thermoplastic material and then forcing it through a die, creating a long sheet or profile of acrylic. The sheets are then cooled, cut to size, and then polished. This process is relatively fast and efficient, and it is used to produce acrylic sheets that are relatively consistent in thickness and quality.

Cell cast acrylic, on the other hand, is made by pouring liquid acrylic into a mold and then curing it. This process results in acrylic sheets that are very consistent in thickness and quality, but it is also more expensive and time-consuming than the extrusion process.

Acrylic sheets made from cell cast process are generally considered to be higher in quality than those made from extruded acrylic, since they have fewer visual imperfections and exhibit less warping. They are also often more resistant to impact, UV degradation and weathering. Cell cast acrylic sheet also have better optical properties, like higher light transmittance, and thus used in more demanding application like signages, aquariums, and skylights.

Extruded acrylic sheets are less expensive and also available in a variety of colors, thicknesses and sizes, They are commonly used in various applications like window replacements, store fixtures, and other items where clarity is not so important.