These are my CRTs. The Toshiba I got at an estate sale, the Multitech is from Ebay, and the RCA is from an abandoned estate. CRT stands for Cathode Ray Tube. They shoot electrons at a phosphor to display a image for each frame. They were produced from 1897 to 2012; however, they are still produced for niches like airplane cockpits, military, and retro gaming.