>>700344
>Is this something like seeing God
That's a controversial topic. Eastern Orthodox theology states that we can through the energies of God. Catholicism is more vague regarding this, but most seem to deny the distinction of essence and energies and so we cannot see God in this life.
>or thinking about spiritual things?
I think contemplation definitely encompasses this aspect.
>Is this Orthodox and Catholic-only stuff?
I don't think so, last time I checked John Wesley was a very spiritual man, and George Foxx definitely practised contemplation. I don't see why it is exclusive to Catholicism and Orthodoxy, could you elaborate a bit more on what you mean by that?
>What is contemplation?
I would say it is simply "pray[er] without ceasing" (1st Thessalonians 5:17)