correct key?

For example, if I’m in the key of c and I have a sample in f, why do I have to transpose the sample to c?

If you know the difference between C and F, you have already answered your question.

I do know when you play a c major, f major, and a g major, or a 1, 4, 5 , you are playing a chord progression in the key of question is if I transpose my f sample and g sample to c wouldn’t I lose my progression? Sorry if this is a silly question.

If you have samples of C, F and G chords, then you don’t need to transpose them, because they are already the right chords.

If you only sampled one chord - say C chord, then you would need to transpose the sample up 5 semitones to get an F chord and up 7 semitones for the G chord - though they will probably sound a bit odd shifted this far away from the source.

If you transposed your F and G chord samples to C, then all three of your chords would play a C chord. (certainly not what you want)

So you need to transpose only if you have a single C chord sample, otherwise, just play your three sampled chords as they are.

Thanks a lot andyjh.
I think what confused me was that I saw an instructor in a tutorial
transposing all his samples to c.