This being a music forum, I felt that this might be a usable definition:
"What Is Life" is a song by George Harrison and is the first track on side two of his 1970 solo album All Things Must Pass. It was released as the second single from that album in the United States on February 15, 1971 with another album track, "Apple Scruffs," as the B-side. On March 27, "What Is Life" peaked at #10 in the Billboard Hot 100, making Harrison the first member of the Beatles to log two Top 10 solo hits on that chart.
Sorry, I couldn't resist.
Taken from Wikipedia, btw.