in, at, with, by (formal particle)
A formal particle that marks location, means, or time, equivalent to で in casual speech.
にて is the formal written equivalent of the particle で. It can indicate where an action takes place (at/in), the means by which something is done (with/by), or occasionally a time. You will encounter it in official documents, announcements, business letters, and formal speeches. In everyday conversation, using にて sounds stiff and bookish, so stick with で unless you are writing formally or making an announcement.