The difference is that an adjective placed before a noun acts as
an attribute and after a noun it acts as a modifier. There are
some rules as to the position of the adjective, as follows:
Demonstrative, posessive and indefinite adjectives and articles
go before the noun. E.g., Mis tres amigas vienen a la fiesta or
Este nivel de español es intermedio. Superlative or diminutive
adjectives go before the noun. E.g., ¿Cuál es el mejor libro que
has leído?, La peor película que he visto or Es la mejor manzana
que he probado. To express emphasis, you place the "measuring"
adjective before the noun, e.g., La hermosa niña de ojos azules
or El asqueroso perro de mi vecino. If you use two or more
adjectives that refer to the same noun they are placed after the
noun. Examples: La mujer guapa e inteligente, La casa es grande
y bonita. In certain cases a change in the position of the
adjective alters its meaning, as in your example. Another
example is El señor pobre vs El pobre señor. In this example El
señor pobre means t