What is Docker BuildKit and what advantages does it provide?

BuildKit is Docker improved build engine with enhanced features and performance. Key features: 1) Parallel builds, 2) Build cache optimization, 3) Secrets and SSH forwarding, 4) Multi-platform builds, 5) Advanced Dockerfile syntax. Enabling BuildKit: export DOCKER_BUILDKIT=1, docker build . Advanced features: Cache mounts (RUN --mount=type=cache,target=/root/.npm npm install), Secrets (RUN --mount=type=secret,id=mypassword cat /run/secrets/mypassword), SSH forwarding, Multi-platform builds (docker buildx build --platform linux/amd64,linux/arm64 -t myapp .). Benefits: 2-10x faster builds, Better caching, Parallel execution, Enhanced security, Cross-platform support.