SVG gradient position

How to use the gradientUnits property, in SVG linear and radial gradients, to change the gradient dimensions and their relation to the artboard. Both examples have the same shapes, and linearGradient applied to them, one with the gradientUnits relative to the artboard (left), the other relative to the shapes (right).

An SVG gradient that is applied in relation the artboard, using the gradientUnits property . Each separate shape appears to blend.
Without the gradientUnits property , the gradient dimensions will be applied relative to the rect shape. Each shape is clearly defined, with the gradient starting and ending within the shape bounds.