This is the 116th most frequent Catalan word.
explica
"Explica" means "explains" in English.
In this question, "explica" is used in a polite form of address (second person singular in formal speech) to request an explanation.
Per què no m'explica el que va passar ahir?
Why don't you explain to me what happened yesterday?
Here, "explica" metaphorically refers to the act of a written work narrating or conveying a narrative.
La novel·la explica una història apassionant sobre l'amistat.
The novel tells an exciting story about friendship.
The word "explica" is used as a third-person singular form of the verb "explicar," meaning "to explain." Here, it describes an action where someone is clarifying or conveying information.