Cocinar vs. cocer vs. preparar
The Spanish language has different terms for the overall process of food preparation, three of which are 'cocinar', 'cocer' and 'preparar'. They are not completely interchangeable, as each word pertains to specific aspects of cooking.
Cocinar
This word refers to the generic act of cooking. It encompasses all types of cooking processes.
Mi abuela adora cocinar los domingos.
(My grandmother loves to cook on Sundays.)
Cada día cocino un plato diferente para la cena.
(Every day I cook a different dish for dinner.)
Cocer
'Cocer' is a more specific term that refers mostly to boiling or simmering food. It generally involves cooking in water or other liquid.
Voy a cocer las papas para la cena.
(I'm going to bake the potatoes for dinner.)
Debemos cocer el arroz durante 20 minutos.
(We must cook the rice for 20 minutes.)
Preparar
'Preparar' means to prepare. It can be used for all stages of meal preparation, including washing, cutting, seasoning, and cooking.
Por favor, ayuda a preparar la comida.
(Please help prepare the food.)
Estoy preparando la cena para esta noche.
(I am preparing dinner for tonight.)
Summary
'Cocinar', 'cocer', and 'preparar' are all related to the process of making food but have different uses in context. While 'cocinar' describes the overall act of cooking, 'cocer' refers more specifically to boiling or simmering food. Lastly, 'preparar' relates to all stages of meal preparation, from raw ingredients to finished dish.