I am not sure about how common they are today, but I do know that thoses dics were used as the primary medium for the reproduction of music until the ending of the 20th century
Not at all, they were both used to produce music until the late 20th century.
Are you familiar with phonograph records? I've never heard of them. Yes, I have heard of them. They are a medium to store analog sound which is known as Gramophone in British english, did you know about that ? I had no idea. What else do you know about them? Well, I also know that the grooves start close to the periphery of the disk and only ends close to the center Very interesting. Do you know what they are made of ? I do know that. Starting in the 50's, the commom material used became polyvinyl chloride Nice to know that. Are they still common today ?
The phonograph disc record was the primary medium used for music reproduction until late in the 20th century.