a depiction of scenery
"The scenic backdrop in the movie was created entirely through computer-generated imagery to show a fantasy landscape."
having beautiful scenery; picturesque
"The scenic drive along the coast offered breathtaking views of towering cliffs and turquoise waters."
In plain English: Scenic describes something that has beautiful views to look at while you are there.
"The scenic route offers beautiful views of the mountains and lakes."
The word scenic comes from the Latin scēnicus, which originally meant "of or pertaining to the stage." It traveled into English via Middle French, keeping its theatrical meaning.