ASICs are like sports cars built purely for speed on the racetrack, but hopeless on a rocky mountain trail. In Bitcoin, ASIC miners compute SHA-256 hashes much faster than general-purpose computers. That efficiency leads to better odds of finding a valid block, thus earning block rewards.

Their advent marked a shift from hobbyist GPU or CPU mining to industrial-scale operations, as anyone using non-ASIC hardware was quickly outcompeted. ASICs have driven the ongoing debate about mining centralization, with huge mining farms emerging where electricity is cheapest. They also underline how proof-of-work, when specialized, becomes incredibly secure—though it comes with a substantial energy footprint.