Learn Spanish (Spain): El redactor ha imprimido el titular en la impresora. - The editor has printed the headline on the printer.

Imprimir (to print) is one of the very few Spanish verbs with two accepted past participles: the regular imprimido and the irregular impreso. Both are completely correct and interchangeable when forming compound tenses like the present perfect shown here. However, when used as an adjective, you must use the irregular form (for example, el titular impreso).

I thought the word for editor was el editor. Why use el redactor here?

This is a common false friend. In Spanish, un editor usually refers to a publisher or someone running a publishing house. A person who writes, drafts, or copyedits text for a newspaper, magazine, or agency is typically called un redactor.

What is the difference between el titular and el título?

El titular specifically refers to a news headline. El título is the general word for the title of a book, movie, or song, or for an official academic degree.

Why do we use en instead of sobre to say on the printer?

The Spanish preposition en covers both in and on. Unless you specifically need to emphasize that a physical object is resting on top of the machine (which would use sobre or encima de), en is the most natural preposition to use when talking about completing a task on a device.