QUICK ANSWER
"Buenas noches" is a form of "buenas noches", a phrase which is often translated as "good evening". "Buena noche" is a phrase which is often translated as "good night". Learn more about the difference between "buena noche" and "buenas noches" below.
buena noche(
bweh
-
nah
noh
-
cheh
)A phrase is a group of words commonly used together (e.g., once upon a time).
1. (general)
a. good night
Los dos equipos dieron lo mejor de sí. Fue una buena noche para el fútbol internacional.Both teams performed at the top of their game. It was a good night for international soccer.
buenas noches(
bweh
-
nahs
noh
-
chehs
)A phrase is a group of words commonly used together (e.g., once upon a time).
1. (salutation)
2. (farewell)