What does thermally broken mean on this door?

The aluminum frame has a barrier between its inner and outer sections. That barrier slows heat moving through the metal and reduces condensation on the frame in cold weather.

Is it better than a wood exterior door?

Aluminum will not rot, swell or warp and needs no repainting. Wood looks warmer and can be refinished, but it needs regular upkeep and can absorb moisture.

What comes in the box?

The listing describes a pre-hung door unit. That means the door slab comes already mounted in its frame, ready to set into the rough opening.

Does it suit a humid or coastal climate?

Aluminum handles moisture and salt air better than wood. Check that the hinges and other hardware are rated for coastal exposure, since those parts can still corrode.

Will it fit my existing doorway?

A pre-hung door is sized to its frame, so measure your rough opening and compare it with the unit's frame dimensions before ordering. An existing opening may need adjusting.

How hard is it to install?

A pre-hung unit is faster to set than a slab in a separate frame, but it is heavy and needs two people. Plumb and square the frame, then seal it against weather.