Pez vs. pescado
In Spanish, the terms pez and pescado both translate to fish in English, but they are used in distinct contexts. The key difference lies in whether the fish is considered alive and swimming or it has been caught for consumption.
Pez
A1This word is used to refer to a fish while it is still alive and in its natural aquatic habitat. When discussing marine life or talking about a fish in an aquarium, you would use pez.
El pez nada en el océano.
(The fish swims in the ocean.)
Mi pez dorado vive en una pecera.
(My goldfish lives in a fish tank.)
Pescado
A1This word refers specifically to fish that have been caught (usually for human consumption). When discussing cooking or eating, we use pescado.
Hoy comeremos pescado para el almuerzo.
(Today we will eat fish for lunch.)
El salmón es un pescado muy popular.
(Salmon is a very popular fish.)
Summary
Pez and pescado both refer to fish, but in different contexts. Use pez when referring to live, swimming fish; use pescado when referring to fish as food. It's one of the nuances of Spanish language that showcases its rich diversity.