Colors or values can be added the ramp by clicking on the + or on the desired position on the ramp. The curve view can be expanded by clicking on the small down arrow.
The number of the selected color point.
The location of the selected color point along the ramp from 0-1.
Color/Value at the given point on the curve or gradient.
Tube with a ramp RGB applied. Note the state_float used as the input because the ramp shader has no knowledge of the objects UVs.
Tube with Ramp Float used as displacement showing constant, linear and Catmull-Rom interpolation
Ramp RGB and Ramp Float combined with some noises