Custom Burned Chips

[XTheOwl]

When people say they have custom burned chips, does that mean:

A.) They physically took their car into a place that ran dyno tests on their actual car, and programmed a chip just for that auto(with any mods it might have) goig by the test results. In other words, each chip is different, even between cars with that are the exact same year, make, model, etc.

B.) They have a chip that is programmed going by VIN or just knowing what year and engine the car is/has.

Sorry if this came out confusing

Thanks,

xto