Any discussion about music and sound reproduction will eventually make reference to how it is presented to the listener. Of course, it all began with monophonic, but over the years technology has provided more and more choices starting with stereophonic, followed by a host of multi-phonic formats like quadraphonic, Dolby 5.1 and 6.1. Monophonic (mono) has just one prerecorded channel. Stereophonic sound (stereo) has two distinct channels, left and right.
Regarding stereo recordings, when stereo first came out it was a brand new world and exactly how to represent a recording in a stereo format was very subjective. Artists and engineers had varying opinions as to how much stereo effect (directional effect) was appropriate. Consequently, many early stereo recordings sound very gimmick-y and unrealistic with too much differentiation between the left and right channels.
Beginning with the comparison of Mono and Stereo recordings, it was typical that both mono and stereo records were made from the late 1950s until around 1970 when they ceased production of mono records. While the records were created from the same performance that is not to say that they sound exactly the same.
Finally let me touch upon quadraphonic recordings as they appeared on vinyl records. There was no industry standard when it came to defining exactly what quadraphonic was, so many different types of quadraphonic techniques and their resulting consumer products appeared on the market.