Is the Siena wood-burning or gas?

It is a wood-burning fire pit. You load logs and light them yourself; there is no gas burner, tank or line.

Can I use it on a wooden deck?

A wood-burning fire pit radiates heat downward and throws embers, so it is safest on a non-combustible surface such as stone, gravel or concrete, kept clear of overhangs and flammable material.

How is it different from a gas fire pit?

Gas gives instant, adjustable flames with no smoke or ash. The Siena gives a real wood fire with more heat and atmosphere, but you supply fuel, start the fire and clean out ash.

What do I need to run it?

Dry firewood, a way to light it, and a safe non-flammable spot away from structures. A cover and a poker are useful for keeping it dry and tending the fire.