Definition from Wikipedia:
An architectural structure is a free-standing, immobile outdoor construction.
The structure may be permanent. Typical examples include buildings and nonbuilding structures such as bridges, dams, electricity pylons, and radio masts.
Some structures are temporary, built for ephemeral events such as trade shows, conferences or theatre, and often dismantled after use. Temporary structures have fewer constraints relating to future use and durability, and often comprise lightweight forms such as tents, which are quicker to erect, take down, and re-use.
A link to a structure based on structural parameters
Below is a list of useful Grasshopper experiments and definitions related to structure and skin:
A basic braced frame structure