Well that's the 1980s for you (not that I remember much. I was born in 1981).
The one on the right is Alison Moyet.
The one on the left is Vince Clarke.
Prior to founding Yazoo, Clarke was a member of Depeche Mode, which he left in 1982. Since then, Depeche Mode have become the most successful electronic band in history.
Moyet and Clarke had known each other since school.
Yazoo split in 1983. Moyet went on to have a moderately successful solo career, whilst Clarke teamed up with Andy Bell to form the hugely successful electro-pop band Erasure, which is still going strong today.
Erasure - "A Little Respect" (1988 )