What is "g-cloud"

The G-Cloud (or G-Cloud complex) is an interstellar cloud located next to the Local Interstellar Cloud. It is unknown whether the Solar System is embedded in the Local Interstellar Cloud or in the region where the two clouds are interacting, although the Solar System is currently moving towards the G-Cloud. The G-Cloud contains the stars Alpha Centauri (a triple star system that includes Proxima Centauri) and Altair (and possibly others).