The phrase refers to software or online services designed to extract the audio component from video files hosted on YouTube and subsequently save it as an MP3 file. These tools enable users to acquire audio tracks from YouTube videos, converting them into a widely compatible audio format. An example would be using a specific website or application to obtain an MP3 file containing the music from a YouTube music video.
The significance of these utilities lies in their ability to provide offline access to audio content found on YouTube. This functionality serves various purposes, including listening to music, podcasts, or lectures without requiring a continuous internet connection. Historically, the desire to archive and repurpose online media has driven the development and proliferation of such tools.