When someone or something appears, they move into a position where you can see them.
A boat appeared on the horizon.
You also use appear to say that something becomes available for people to read or buy.
His second novel appeared under the title ‘Getting By’.
It was about the time that smartphones first appeared in the shops.
If something appears to be true, it seems to be true. Similarly, if something appears to be a particular thing, it seems to be that thing. Appear to is more formal than ‘seem to’.
The aircraft appears to have crashed near Kathmandu.
Their offer appears to be the most attractive.