What is a "roller skate"?

A roller skate is a type of shoe with wheels attached to the bottom, designed for skating and other recreational activities. The first roller skates were invented in the 18th century, but the modern version of roller skates, with four wheels arranged in a square pattern, became popular in the 20th century. Roller skates can be used for indoor or outdoor skating, and are available in a range of styles, from basic recreational skates to high-performance models designed for aggressive skating or roller derby. Roller skates may have a traditional laced closure or may use more advanced mechanisms like buckles or ratchets to ensure a secure fit. They are popular among children and adults alike and can be used for fitness, socializing, or competitive purposes.