Refers to a pair of performers, especially in music, or any two people working closely together. Loanword from Italian.
from Italian
彼らは人気のデュオとして全国ツアーを行った。
They went on a national tour as a popular duo.
The two have been a duo since their high school days.
あのデュオのハーモニーは本当に美しい。
The harmony of that duo is truly beautiful.
彼は幼なじみとデュオを組んで歌手デビューした。
He made his singing debut, forming a duo with a childhood friend.
The two formed a new duo last year.
After pursuing solo careers, they are performing as a duo again.
ソロ means performing alone, the direct opposite of デュオ, which means performing as a pair.
デュエット refers to the duet performance or song itself, while デュオ refers to the two-person group or unit performing it.
class of students · group of people; team; crew; party · set; lot; bunch; assortment; deck or pack · organized-crime syndicate; crime family · typesetting; composition
Borrowed from Italian 'duo', meaning a musical piece for two performers or the performers themselves.