Are these two separate trees or one?

The set is two pieces, so you get a pair of 48-inch topiaries. They are meant to be placed together, for example on either side of a door.

Can they stay outside all year?

They are listed as suitable for outdoors. The foliage is plastic and the trunk is wood, so a sheltered spot out of constant direct sun and standing water will last longer.

Do they need assembly?

Expect some setup, since the trees ship as pieces. The trunk and foliage usually slot or screw together, and a weighted base or planter helps them stand steady.

Do they come with lights?

The specs mention lighting as a property, but they do not say whether lights are built in or sold separately. Check the box contents before you count on lit trees.

How do they compare with live boxwood?

They keep their shape and color all year with no watering or clipping. Live boxwood looks more natural and can be shaped, but needs care and can suffer from blight.