Adobe Flash Player was a software application used to view multimedia content, such as animations, videos, and interactive games, on the web. It enabled developers to create rich internet applications and was widely used for online video streaming and interactive websites. However, due to security vulnerabilities and the rise of more modern technologies like HTML5, CSS3, and JavaScript, support for Flash Player was officially discontinued by Adobe on December 31, 2020. As a result, many websites transitioned away from Flash, leading to a decline in its usage and relevance in web development.