The 'lytag.js' script is part of the Flowplayer video platform, designed to gather comprehensive analytics regarding video content consumption on websites. It monitors various user interactions with embedded video players, such as video starts, pauses, completions, seeking events, and overall watch time. This data is then transmitted to Flowplayer's analytics backend, providing website owners with detailed insights into video performance, audience engagement, and consumption patterns. The script helps in understanding how users interact with video content and in optimizing video strategies.