Gram is the unit of mass, and the symbol is G. One gram is the mass of18×14074481c-12 atom. The weight of one gram is approximately equivalent to the weight of one cubic centimeter of water at room temperature.
Kilogram is the unit of mass, and mass is equivalent to how "heavy" a thing is every day. However, quality is actually an attribute with "inertia"; In other words, an object will tend to maintain its current speed without external force.
When an object with a mass of one kilogram is subjected to a force of one Newton, it will get an acceleration of one meter per square second (about one tenth of the acceleration of the earth's gravity).
The weight of matter depends entirely on the local gravitational intensity, while the mass is constant (assuming that the mass does not move relative to the observer at relativistic speed).