Plain-language answer: HF prediction software turns a propagation model and station inputs into estimates of usable frequencies, signal strength, or reliability.
Why operators care
Different programs may share an engine yet use different defaults, maps, antennas, noise assumptions, and solar data. A polished graph does not guarantee correct inputs.
How to use it well
Save the model version and complete scenario, replace generic antennas with realistic patterns, and compare predictions with current observations.
The common mistake
Comparing two programs without first making their inputs and reliability criteria equivalent.
Operating boundary
Predictions, reports, schedules, and mode descriptions guide a decision; they do not override current regulations, equipment limits, exact station conditions, or what the operator verifies on air.
