Adobe Flash, formerly known as Macromedia Flash is a platform used for creating and delivering multimedia content on the Internet, such as animations, Rich Internet Applications, and more.
Adobe Flash content is rendered on browsers with the help of the Adobe Flash Player. Think of Adobe Flash as the technology, while Adobe Flash Player is the tool that renders the content created in Adobe Flash.
So, next time your browser plays multimedia content, Flash might be the technology behind it.
Adobe will officially end support for Flash on December 31, 2020 and Flash content will be converted to HTML5.