Input[XYZ ]

This vector will be recalculated.

Old Range Min[XYZ ]

Old Range Max[XYZ ]

New Range Min[XYZ ]

New Range Max[XYZ ]

These values define an input and an output range that is used to convert the input vector. The calculation follows this scheme:
Let's assume an input range between 0 and 2 with an Input of 1.
This input is exactly in the middle of the input range, which we can also interpret as 50%.

With an output range of, for example, between 5 and 25, this results in the output value of 15 (5 + 50% of 25-5) when considering the 50% value.

Clamp To New Range

These settings automatically restricts the recalculated input value to the output range (i.e. to values from Output Lower to Output Upper).