Following the 1947 invention of the cathode-ray tube amusement device, the earliest known interactive electronic game as well as the first to use an electronic display, the first true video games were created in the early 1950s. Initially created as technology demonstrations, such as the Bertie the Brain and Nimrod computers in 1950 and 1951, video games also became the purview of academic research. A series of games, generally simulating real-world board games, were created at various research institutions to explore programming, human–computer interaction, and computer algorithms. These include OXO and Christopher Strachey's draughts program in 1952, the first software-based games to incorporate a CRT display, and several chess and checkers programs. Possibly the first video game created simply for entertainment was 1958's Tennis for Two, featuring moving graphics on an oscilloscope. As computing technology improved over time, computers became smaller and faster, and the ability to work on them was opened up to university employees and undergraduate students by the end of the 1950s. These new programmers began to create games for non-academic purposes, leading up to the 1962 release of Spacewar! as one of the earliest known digital computer games to be available outside a single research institute.
Throughout the rest of the 1960s, digital computer games were created by increasingly numerous programmers and sometimes sold commercially in catalogs. As the audience for video games expanded to more than a few dozen research institutions with the falling cost of computers, and programming languages that would run on multiple types of computers were created, a wider variety of games began to be developed. Video games transitioned into a new era in the early 1970s with the launch of the commercial video game industry with the display of the coin-operated arcade game Galaxy Game and the release of the first widely available arcade game Computer Space, and then in 1972 with the release of the immensely successful arcade game Pong and the first home video game console, the Magnavox Odyssey, which launched the first generation of video game consoles.
https://en.wikipedia.org/wiki/Early_history_of_video_games