Drivechain allows BTC to travel back-and-forth to other software applications (called “sidechains”). Thus, BTC-owners can opt-in to new features or tradeoffs. Those who don’t opt-in, never need to care what any sidechain is doing.

As with the Lightning Network, DC-users move their coins into a “layer-2” – a zone where BTC can change hands an unlimited number of times. Eventually, just the net effect of these transfers is recorded back on layer-1.

Bitcoin Core can’t observe any layer-2 (by design), so we need a way to discourage fraudulent “netting”. LN counters theft via “justice transactions”; DC via forsaken mining revenues. LN-netting is private and instant; DC-netting is public and VERY slow (once per ~3 months).

Key benefits – only obtainable via Drivechain:

Three existential threats to BTC are neutralized – altcoin-competition, hard fork campaigns, and extension block campaigns.
BTC development becomes anti-fragile with respect to CoreDev mistakes.
BTC maintains hashrate security in the long run.
BTC can scale to credit-card level txn-processing – without changing the CONOP of Bitcoin Core. These cheap txns have optimal fungibility and supply vital pretext to the BTC ecosystem.
BTC gains new, experimental abilities, especially P2P event derivatives.