A curtain wall is a non-structural glass covering on a building that can be made of a lightweight material, reducing construction costs. Curtain walls now are typically designed with aluminum profile which is an inexpensive solution when you want to create partitions on the outer layer of an architectural structure.
Glass is fitted within the tracks of the curtain wall with the great advantage is that natural light can penetrate deeper within the building.
A curtain wall is designed to resist air and water infiltration, sway induced by wind and seismic forces acting on the building, and its own dead load weight forces.
They can also act as a fire stop, preventing the spread of fire from floor to floor of the building structure.