Lego sets are construction toys that consist of interlocking plastic bricks, allowing users to build a wide variety of structures and models. Each set typically comes with a specific theme, such as Star Wars, Harry Potter, or City, and includes instructions for creating designated designs. These sets cater to different age groups and skill levels, ranging from simple designs for young children to complex models for older enthusiasts. Lego encourages creativity and problem-solving, as builders can modify or combine sets to create their own unique projects.