Banana vs. plátano
The Spanish words 'banana' and 'plátano' both typically translate to 'banana' in English, but regional usage varies widely. In some countries, they are interchangeable while in others, each word refers to a specific type of fruit.
Banana
In several Spanish-speaking regions such as parts of Central America, 'banana' is used to refer specifically to the sweet, yellow fruit commonly eaten raw and is a loanword from English.
Me gusta comer una banana para el desayuno.
(I like eating a banana for breakfast.)
Mi batido favorito es de banana y fresa.
(My favorite smoothie is banana and strawberry.)
Plátano
'Plátano' can mean different things depending on the region. In Spain, it is interchangeable with 'banana'. However, in many Latin American countries, 'plátano' often refers to a type of fruit resembling bananas that is larger and usually cooked before eaten (plantain in English).
Voy a hacer un pastel de plátano.
(I'm going to make a banana cake.)
En mi país los plátanos se fríen y se sirven como guarnición.
(In my country plantains are fried and served as a side dish.)
Summary
'Banana' and 'plátano' serve as two Spanish words for the fruit known in English as 'banana', but their usage may vary by country or region. Some Spanish speakers use 'banana' to refer exclusively to the sweet fruit commonly eaten raw, while 'plátano' may either refer to the same fruit or to plantains depending on the region.