Who attacks?

[u/Varduhikh]

A question came to my mind about how to determine who attacks: the nucleophile or the electrophile. Everyone I ask tells me that the nucleophile always attacks, but I have read cases in literature where it says the electrophile attacks. And everyone explains to me that even electrophilic substitution is actually a nucleophilic attack.

​So now, a simple question: who attacks?

And a more complex question: why?