What is the meaning of -에?

at (indicates that the preceding noun functions as a locative adverb, making a place or location)

at (indicates that the preceding noun functions as a temporal adverb, making a point in time)

to (indicates the direction or destination of movement)

because of (marks the cause or reason behind an action)

with, by (marks the noun that acts as the stimulus or cause for a reaction or movement)

to, about, in (marks the noun as the recipient or target that an action affects or within which a state is realized)

for (indicates that the preceding noun represents a goal or purpose)

by (indicates the method or means by which an action is performed)

in (marks the condition or state in which an action occurs)

per (marks the preceding noun as a reference standard or unit of measure, used for evaluation, distribution, or calculation)

than (indicates the object of a direct comparison between two entities, without implying a measured standard)

as (shows that the preceding noun represents the role or position assumed)

within (conveys that the scope or range is confined to a specified group or area)

about (with expressions like 관하여 or 대하여. indicates the subject or object that is being specified for discussion)

plus (denotes that something additional is added to what has been mentioned)

and (functions as a coordinating postposition that links two or more nouns of equal status)

Source: wiktionary.org