A plastic construction set is a type of toy that consists of interlocking pieces made of plastic, such as LEGO. It allows children to build structures and models of various shapes and sizes. LEGO is the most popular brand of plastic construction sets, and it has been around since 1949. The pieces are designed to fit together easily, allowing children to create their own designs. LEGO sets come in a variety of themes, from castles to space ships, and can be used to teach children about engineering and design.