If you're fascinated with vinyl records and would like to see how they're made, check out these two videos.
This one
https://www.youtube.com/watch?v=xUGRRUecBik
shows how the pattern of the sound is transferred from the master recording to the master disk that will later by used to stamp the vinyl disks.
The second one
https://www.youtube.com/watch?v=IReDh9ec_rk&t=9s
shows the automated method of stamping the actual disks. There is also a manual method for smaller production quantities, as is used and can be seen at Third Man Records in Detroit, which also has automated equipment.
This informative video, which Thin Air Audio recommends watching before buying a used reel to reel tape recorder, starts with a real-world example of the uncertainty involved with buying a used machine. Also, beginning around 12:30 there’s good information on operation and maintenance of recorders in general and multitrack (4 channels or more) recorders in particular.