npm (and the alternatives — yarn, pnpm, bun) is the package manager underlying every JavaScript project. The npm registry has more than 3 million packages; pnpm and bun have become the default choices for new projects because they handle disk usage and install speed better than classic npm.
Most package-manager courses cover lockfile mechanics, workspace / monorepo configuration (npm workspaces, pnpm workspaces, Turborepo, Nx), publishing your own packages, and the security side (npm audit, dependency review, supply-chain attacks like the recent ones on node-ipc and colors). Understanding what a lockfile actually means saves more debugging time than people expect.