You use "del" when in a statement is this: El coche de "Del" es la unión de la preposición "de" y el artículo "el". Es recomendable utilizar "del" en lugar "de el". De + el = Del. del = de + el It's like a contraction. Incorrect--> El pescado es de el mar. Correct -->El pescado es del mar.

de (preposition) el (definite article masculine) del (a contraction is required when de+el go together the result is "del")

Del is a great way to combine "de" and "el" which makes speaking easier when using the masculine form of "the" in Spanish. However, you don't do that with "la"-the feminine form of 'the'. Example: Las chicas DEL aeropuerto. Las chicas DE LA escuela.