Percha vs. gancho
The Spanish language has varying terms for similar things, depending on the context and country. In this case, we're looking at the terms percha and gancho, both of which translate to hanger in English.
Percha
A2Percha is the common term used for hanger in Spain. It usually refers to the entire tool- a curved piece of wood, metal or plastic with a hook, used for hanging clothes. The term percha encompasses both the hook and the body.
He colgado mi abrigo en la percha.
(I have hung my coat on the hanger.)
Voy a comprar perchas de madera para mi nuevo armario.
(I am going to buy wooden hangers for my new wardrobe.)
Gancho
A2Gancho translates directly to hook. In certain Latin American countries, it can be used to mean a hanger, but usually it is used more generally to refer to any kind of hooking device, not just those involved in clothing storage. It does not necessarily imply the shape of a traditional clothes hanger, as percha does.
El cuadro cayó porque el gancho estaba flojo.
(The picture fell because the hook was loose.)
Voy a utilizar este gancho para colgar mi bolsa.
(I am going to use this hook to hang my bag.)
Summary
Percha and gancho are two Spanish words that can be translated into English as hanger. However, they are used differently depending on the context and region. Usually, percha refers to a clothes hanger specifically, whereas gancho refers more broadly to any form of hook.