Force
In physics, a force is any interaction that, when unopposed, will change the motion of an object. A force can cause an object with mass to change its velocity (which includes to begin moving from a state of rest), i.e., to accelerate. Force can also be described intuitively as a push or a pull. A force has both magnitude and direction, making it a vector quantity. It is measured in the SI unit of newtons and represented by the symbol F.
G-force
The unit of measure of acceleration in the International System of Units (SI) is m/s. However, to distinguish acceleration relative to free fall from simple acceleration (rate of change of velocity), the unit g (or g) is often used. One "g" is the acceleration due to gravity at the Earth's surface and is the standard gravity (symbol: "g"), defined as  metres per second squared, or equivalently  newtons of force per kilogram of mass. Note that the "unit definition" does not vary with location—the g-force when standing on the moon is about 0.181 g.