Difference Between "Active" and "Passive" Volume Pedals

[BassIsBad]

The way I understand it, the only difference is the pot, and the impedance they have. For example, the Earnie Ball VP Jr. active version have 25k pots, and the passive ones have 250K pots (I think). My question is, does it really even matter? Could the "passive" version be used with active instruments, and vise-versa?

[ChetMagongalo]

I've read that you buy them depending on where in your pedal chain you want to put them. Either in front or between other pedals. I want to eventually get a vol pedal to run at the end of the chain just before loopers or something

[leaves turn]

active ones steal a precious, precious power slot

I just don't get volume pedals. Swells are cool and all but even a scrub like me can do them easily with guitar volume if I take the pick out of my hand.

[BassIsBad]

I'm not talking about active in the since that it requires a power source. I mean that it is either designed for active or passive electronics.