Anodized aluminum sheets are aluminum that has been treated with an electrochemical process to increase its thickness and durability, forming a protective oxide layer on the surface. This process enhances corrosion resistance, wear resistance, and allows for a wide range of colors. Non-anodized aluminum sheets, on the other hand, have not undergone this treatment and are more prone to corrosion and less durable. They also have a more limited color range and are generally softer and less resistant to wear.