"Greatest hits" refers to a compilation of an artist's most popular and successful songs, often released as an album. These collections typically feature tracks that have received significant radio play, charted well, or become fan favorites over time. They serve as a way for new listeners to discover an artist's work and for longtime fans to enjoy a curated selection of their best material. Many artists, such as The Beatles or Madonna, have released greatest hits albums to celebrate their careers and highlight their most impactful songs. These albums can also be a strategic move to boost sales or introduce a new audience to an artist's music, often including remastered versions or previously unreleased tracks.