The case is the wood that surrounds the opening, the portal is the actual opening.
In language a door can be considered a synonym for portal. If an individual can open a door, then in the same context an individual can open a portal. A portal is simply a gateway, or entry-point, to another location.
The prefix for portal is "port-", which means a door or entrance.
A portal.
A door is a physical barrier that opens or closes to allow passage through an entry point, typically found in buildings or vehicles. A portal is a more mystical or fantastical concept that serves as a gateway or connection between different realms or dimensions, often associated with magical or spiritual elements.
Portal door
a door
Opening, portal, hole, entrance.
its not exactly a portal its more like a door outside
An archway/door with a sculpted design with figures above it.
Barbican
doorway, portal, opening, entrance, entry, exit
Portal. More broadly, entree´and access.