Mixers are amplitude modulators.
One signal modulates the amplitude of the other.
Trigonometrically we have -

2*Sin(A)*Sin(B) = Cos(A-B) - Cos(A+B)

Where the A-B and A+B terms are appropriately described as "the products".

In practice there are a great number of unwanted products output from a
mixer because many harmonics of A and B are generated in the process and all
continue to inter-modulate each other.

The wanted product, the IF, is usually A-B or A+B.
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Regards from Reg, G4FGQ
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