A hinged construction on an artificial Christmas tree refers to the way the branches are attached to the trunk of the tree. Rather than being individually attached or pre-formed into a shape, the branches are attached to the trunk in sections, with each section being hinged to the next.
This allows for the tree to be easily assembled and disassembled for storage, as well as making it more flexible in terms of shaping and arranging the branches.
It's a popular design for artificial trees as it makes it easy to put up, take down and store. Additionally, hinged construction allows the branches to be more durable and resistant to damage during assembly and disassembly compared to other types of artificial trees.