From Coastal Wiki
Definition of Gabions:
Gabions are wire, stone filled cages or mattresses and are normally used to retain or protect slopes from erosion e.g. along eroding coasts
This is the common definition for Gabions, other definitions can be discussed in the article
Gabions are sometimes used to protect sand dunes, a use which is often inappropriate given the soft and dynamic status of mobile foredunes. An example of this is given in the article Light revetments built-in into artificial dunes.