Volatility has two meanings in the same sentence. One is what the market thinks will happen, priced into the option. The other is what happened, measured from the tape. The difference is the whole trade.
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Print two volatilities with windows
Write both numbers with windows
Before you run it, say out loud what it will print. Then open the answer.
Compute the difference
Before you run it, say out loud what it will print. Then open the answer.
Change the window and recompute
Before you run it, say out loud what it will print. Then open the answer.
A number without a window is a number that cannot be argued with. The window is what makes it falsifiable.
A realized estimate computed once and cached is a number that stops being about the market. Recompute on the same cycle as the data.
Implied comes from a price, realized comes from history. They share a unit only after the same assumptions are applied to both.
Realized volatility over ten days and over two hundred days are different facts. A strategy that uses one window chose a horizon.
Implied above realized is a market that expects more movement than history shows. That is a claim about the future, not the past.