Yes the proofs are made with a special blank and the dies are special also. The coin is also struck more than once. Proof coins are made for collectors, so the mint sells them for more money and in the case of the American Eagle coin, mint far fewer than the uncirculated type, which are made just like regular coins are. For an example the 1994 proof 69 silver eagle trends for $250, while the uncirculated one trends for $50 is MS-69 or only $20 if in grade Mint State 64. I have been lucky over the years and have seen some proof coins from the 1800's that were just out of this world.