And we should advise upfront, knowing how locks work is not going to help you to pick them.
As shown in the picture below, there are four key components in a lock as follows:
There are two pins in every chamber and it is the location of those pins vertically that determines whether the key can be rotated or not. The key can be rotated only when the join between all top and bottom pins is located at the join between the barrel and the cylinder. This is called the shear line and then allows the barrel to turn inside the cylinder. So as shown in the previous picture above, these pins in all six chambers have been pushed to the right height by the key so as to form a shear line at the right location and allow the key and barrel to then be rotated.
Now the second picture below shows what happens when an incorrect key is inserted into the lock. The pins are lifted to different heights and as you can see Pin 1 and Pin 4, if numbering from the left, have the pins at the wrong height and aren’t allowing a shear line to be formed at the join between the cylinder and barrel.
So, think you could pick a lock with 2 hair pins? Like so much you see on TV, it is guff!!