12 inches in radius, the LP turned at 33 + 1/3 rotations per minute, giving you twenty to thirty minutes per side of music, and had been doing so since 1948. The LP's came in cardboard sleeves. Inside the sleeves, the record sat inside a paper sleeve so that it would not be harmed as you slid the record into and out of the carboard sleeve. The center of the LP had no recording on it, instead bearing a label telling you about the album. The cover told you about the album as well. The front contained the cover art and titles, while the back contained a track listing, notes, and other interesting tidbits. Sometimes the slipcase contained information and pictures as well.
LPs were usually black, although they didn't need to be. Novelty records were often released in different colors. Later in the era, picture disks were sold. I had a few in my collection. They were essentially clear vinyl over a picture layer. The disks themselves didn't even need to be round. Some novelty records had odd shapes, and some cereal boxes came with 45 rmp single-sized records printed onto them. The quality was lousy, but those square atrocities did play.
When records could not be sold, they were "returned", a hole was drilled through the cover, and then they were sold as remainder. You could buy music cheap that way if you didn't mind buyinig something 5-10 years old. Most of my cutouts were pretty lackluster, but some were fun.
In college, my music store of choice was Books, Strings, and Things. They had a square album stand in the middle of the floor, with another stand off to one side. I loved looking through all those records, flipping from one to the next. A few blocks away from that was a used record store, where you could get even more bargains. At home, my favorite record place was Kemp Mill Records, which were not only cheap, but had some of the best ads on the radio. Their continuous sales were always wacky. Eventually they tried to act corporate and got their lunch money taken away.
At the end of the LP era, you could buy vinyl for dirt cheap, but I did not keep my act together to snap up the remainders. My computer equipment kept sucking up my money.
I do still have a turtable, which is the fancy word for record player, but I never use it. I could, I supposed, by my daughter camps in my office playing Minecraft, which makes listening to vinyl rather difficult.