Mobiliario vs. muebles
The Spanish words 'mobiliario' and 'muebles' both translate to the English word 'furniture', but there is a subtle difference in their usage and context. Both words are used frequently and interchangeably, but their meaning changes depending on the context in Spanish conversations.
Mobiliario
'Mobiliario' refers not only to individual pieces of furniture but also to the ensemble of these pieces that make up an environment.
El mobiliario del salón es muy moderno.
(The living room furniture is very modern.)
Vamos a cambiar todo el mobiliario de la oficina.
(We're going to change all the office furniture.)
Muebles
'Muebles', by contrast, usually refers to individual pieces of furniture.
Voy a comprar un mueble para el televisor.
(I'm going to buy a piece of furniture for the TV.)
Este mueble es muy viejo.
(This piece of furniture is very old.)
Summary
'Mobiliario' and 'muebles' both refer to 'furniture', but there is a distinction in their usage. 'Mobiliario' often refers to a set or collection of furniture as in a whole room or building. On the other hand, 'muebles' generally refers to individual pieces of furniture.