A 78 RPM record is a type of phonograph record that was popular from the late 19th century until the mid-20th century. The term "78 RPM" refers to the speed at which the record spins, which is 78 revolutions per minute. These records are typically made of shellac, a natural resin, and are known for their brittle nature. They usually hold about three to five minutes of audio per side. Unlike modern vinyl records, 78 RPM records have a larger diameter, often measuring 10 to 12 inches. They were commonly used to record music, spoken word, and other audio content. The sound quality of 78 RPM records is distinct, characterized by a warm, vintage tone, but they are more susceptible to scratches and damage compared to later record formats.